Mélanie Jaeck

Robert Lifran

Preferences, Norms and Constraints in farmers' agro-ecological choices. Case study using choice experiments survey in the Rhone River Delta, France

Keywords: Agricultural Technological Choices, Agro-environmental measures, Policy Instruments design, Choice Experiments, Sample Selection Model, Latent classes Model, Random Parameter Model, Rice production, Organic farming JEL Classi…cation : Q12, Q26, Q28

The aim of this paper is to elicit the sensitivity of farmers to payment for agro-environmental services in a context of strong ecological and policy constraints. We present results from a choice experiment survey performed among the whole population of agricultural decision-makers (104) in the Camargue area. Several econometric models have been estimated, the most signi…cant being the Latent Classes one. Three classes have been identi…ed, two of them representing farmers with strong committment to a speci…c technology (either very chemicals intensive or organic farming ), the main class encompassing farmers complying with the norms of the PGI « Riz de Camargue » . The estimated parameters of the utility function, together with the parameter of the monetary attribute provided the monetary value of each relevant agro-ecological attribute and the associated outcomes (average and risk yield). Outcomes of the choice experiments make a strong case for di¤erentiating incentives for spreading environmental friendly technologies.

Introduction

Overall in the world the complex relationship between the technology of agriculture and the environment is placed under scrutiny. The motivations behind that interest are context-dependant, and pertain to market strategies, to strategies of international negotiation or to consumers demand for pesticides-free products. Moreover, the protection of the environment itself could be locally important, specially in area with a great natural heritage value, as in the Camargue area. In such a context, it is di¢ cult to organize the spatial coexistence of intensive agriculture and biodiversity rich area [START_REF] Green | Farming and the fate of wild nature[END_REF]. Mainly because the importance of spillover arising from the intrication of water channel network. If zoning and specialization of zones in segregated spaces for intensive agriculture and biodiversity conservation prove to be not possible or very di¢ cult, then it is worth to look at the distribution of farmers preferences and motivations when they choose their technology of rice production. In each case, balancing between the economic e¢ ciency and the preservation of the environment calls for a careful analysis of the farmers ability to change their practices. Compensating payments could be in some cases necessary to motivate farmers to adopt environmental friendly technologies, but if this is done, they are not automatically undi¤erentiated.

The general assumption of the paper is that farmers face several norms and constraints, but they have nevertheless a scope for expressing individual choices. To test that hypothesis, we used a choice experiment approach. Choice experiments are useful tools to measure either the willingness to accept or the willingness to pay for a set of attributes characterizing goods, services or technology. In that paper, we will present the results of the choice experiment survey performed among the whole population of agricultural decision-makers (104) in the Camargue area, Rhone River delta, France. Moreover, using suitable econometric models, such as Random Parameter Logit or Latent Class Models, it will be possible to asses and characterize the underlying heterogeneity in the farmers technology choices. More precisely, we would like to gain insights on the heterogeneity of farmers preferences regarding both the attributes of the technology and the related compensatory payments. Our use of choice experiment to assess the farmer willingness to accept for speci…c attributes of agricultural technology with di¤erentiated impacts on the environment is , according to authors' knowledge of the literature, original. The results are useful inputs for the design of policy instruments, as long as the regulator is concerned for e¢ cient use of public funds. Helping in the design of di¤erentiated payments. for speci…c environmental services could be a bene…cial outcome of our research 1 .

Litterature review

The issue we are about investigating is related to three di¤erent …elds of the literature : agricultural household models, technology adoption and choice experiments.

The …rst …eld is on the issue of separability between household decision making and farm management and concern the impact of individual utility function of the farm manager, on the choice of farming style and of production technology.

The second …eld of relevant literature concerns the technology adoption process, and how we can discriminate between individual factors and social infuences and interactions pertaining either to collective action or to commercial relationships ?

Finally , it is worth to examine how the question at stake has been investigated in the choice experiments litterature. In their choice of production technology, farmers have preferences not only regarding productivity or pro…tability, but also for various attributes of crops, animals or farming practices. Utility-based adoption models already provide evidence of the importance of the technology's perception by the farmers. Batz et al . show that the speed and the level of adoptipon of a speci…c technology depend on the level of the investment required, the risk involved, and the complexity and the di¢ culties of the task involved in the curse of the implementation [START_REF] Batz | Predicting technology adoption to improve research priority-Setting[END_REF]. Adesina et al. draw attention to the lack of concerns about the farmers' perceptions of the characteristics of the technology. They use a Tobit model of adoption of new and improved rice cultivars in Sierra-Leone, and show that the characteristics of a cultivar that are taken into account are not only those related to yield or input use, but also those related to subjective traits (Adesina et aL, 1993). In a context of subsistence farming, Dalton used a hedonic model of rice traits showing that yield is not a signi…cant factor in the adoption, compared with the length of plant lifecycle, plant height, grains properties (colour, elongation, swelling and tenderness). [START_REF] Dalton | A household hedonic model of rice traits: economic values from farmers in West Africa[END_REF]). Birol and al. analyzed the valuation of agrobiodiversity by Hungarian small farmers in their Home gardens using a choice experiment. They rely on four components of the home-garden system (Richness of crop varieties and fruits trees, crop landrace, integration of crops and livestock production, organic production versus pesticides use). Preferences of small farmers who are oriented toward the satisfaction of the household's needs are described by the mean of the prefered choice sets, and translated into monetary terms [START_REF] Birol | Farmer Preferences for milpa diversity and genetically modi…ed maize in Mexico: a latent class approach[END_REF]). Roessler and Scarpa use a choice experiment survey to assess the preferences of farmers breeding pigs in Vietnam. Based on the set of …ve attributes (growth, reproduction, disease resistance, feeding needs and physical appearence), they identi…ed two types of breeders as folow : « resources driven » and « demand driven or market oriented » breeders. [START_REF] Roessler | Using Choice Experiments to assess smallholders farmers preferences for pig breeding traits in di¤erent production systems in NorthWest Vietnam[END_REF].

Birol et al. presented a latent class approach for the Mexican smallholders facing a choice between the use of the traditional « milpa » system, based on the conservation of genetically diverse maize , and the GM maize [START_REF] Birol | Using a Choice Experiment to Estimate Farmers's Valuation of Agrobiodiversity on Hungarian Small Farms[END_REF]). Dupraz and al. [START_REF] Dupraz | The environmental supply of farm Households, A Flexible Willingness to Accept Model[END_REF] stated that farmers' households are together producers and consumers of the environment they contribute to forging. They accomodate the multifonctionnality of the agricultural production in considering the technological ‡exibility of their environmental supply. Using a contingent valuation survey , they con…rmed that farmers behaviour is in ‡uenced by environmental preferences. More precisely, Davies and Hodge found that two attitudinal factors, « stewardship orientation » and « technological beliefs » were by far the most signiifcant in determining the acceptabilitiy of cross-compliance in the CAP implementation [START_REF] Davies | Farmer's Preferences for New Environmental Policy Instruments: Determining the Acceptability of Cross Compliance for Biodiversity Bene…ts[END_REF]. As a consequence, structural and socio-demographic factors were considerably less impportant. They identi…ed clusters of farmers according to their overall attitudinal orientation. In the same line , Schmitzberger and al., using the concept of « styles of farming » elaborated by Van der Ploeg, established the link between those styles, land use intensity and motivations for biodiversity conservation and participation in agri-environmental programs [START_REF] Schmitzberger | How farming styles in ‡uence biodiversity maintenance in Austrian agricultural landscapes[END_REF]. Van der Ploeg de…ned styles of farming as « a unity of thinking and doing » . Farming styles encompasse human attitudes, farming objectives, economic success and ecological performance. (Van der Ploeg, 1994). Identifying and characterizing the main farming styles inside a set of farmers or an area proved very useful to target some subsets of farmers able to foster a wider adoption of improved weed management strategies by broadacre croppers in Australia [START_REF] Howden | Working with the grain : farming styles among Australian Broadacre croppers[END_REF] Finally, two main conclusions arise from this literature review. The …rst one is related to the importance of subjective factors and preferences in the choices of technology 's attributes (even if few papers are dealing explicitly with the implementation ). The second is about the importance of the diversity of perceptions and farming styles or subcultures (the heterogeneity issue).

Local context

The Camargue is a large area made of intricate …elds, marshes and lagoons in and around the Rhone River Delta (South of France). It belongs to the set of biodiversity hotspots around the Mediterannee Sea registered in the Ramsar convention and also in the European Framework « Habitat, Fauna and Flora » . The area has been recently accepted as part of to the « Man and Biosphere » reserves network. Several local institutionnal arrangements for managing water and biodiversity in the landscape have been …nally designed in a context of con- ‡icting interests (Water Local commission, and Parc Naturel de Camargue). Wheat production and cattle are the main agricultural activities, while various recreational activities, commercial hunting among them, provide high income to landlords. The agricultural production is very intensive, but the use of pesticides and herbicides is highly controlled by several administrative regulations and collective institutionnal arrangements. Irrigated rice growing is used to ‡ush salt from the rootzone after some years of dry farming. However the rice cultivars need to be adapted to the local weather conditions (low spring and autumn temperatures , wind). As a result, the production costs are high and the average yields low. In the actual setting of the CAP, farmers are entitled to uncoupled compensatory payments varying from 400 to 1000 Euros/ ha.

Map 1 : Location of the Camargue area and the surveyed farm

Model of technology choice

We assume that farmer's population exhibits a diversity of preferences regarding the prefered technology. Preferences diversity encompasses both the aversion/addiction to pesticides use, the aversion to the use of seasonal wage workers, the risk aversion, among others. It is well known that agricultural production faces a number of constraints arising from the climat, the local agroecological conditions or the farm's structure. The multiplication of constraints limits the scope for expressing preferences. Moreover, it is often di¢ cult to distinguish constrained choices from unconstrained one. For instance, farmers practising organic farming face several agro-ecological constraints arising from the di¢ uclty of controling the weeds. As a consequence, the long rotation of rice is a necessity (one year of rice , three years of others cereal) in that case. But that constraint could be softened by controling weeds trough manual weeding, which is costly and implies high transactions costs. As a consequence, farmers averse to the use of wage workers could prefer to reduce the rice area.

Assuming a diversity of preferences related to the use of pesticides ant to the use of seasonnal wage workers, we propose to distinguish, as in Schmitzberger, [START_REF] Schmitzberger | How farming styles in ‡uence biodiversity maintenance in Austrian agricultural landscapes[END_REF] two subpopulations, the productivity oriented farmers, the environmentally friendly oriented farmers and a third subset of support oriented farmers. While the farmers belonging to the …rst style of farming are willing to use more pesticides and grow more rice, the second one are willing to avoid them, and accept to use more workers to remove weeds. The third group of farmers belonging to the support optimizers could choose either one technology or another, depending of what is giving the more pro…table outcome.

Figure 1 shows how the production possibilities frontiers, expressing the diversity of technologies, could …t with the preferences related to the corresponding farming styles.

Survey design and data collection

Before proceeding to the survey implementation, we gained the support of the main stakeholders in the Delta, the rice growers side (Centre Français du Riz, Syndicat des Riziculteurs de France et Filière, SRFF) and the Environmental and Landscape Agency side (Parc Naturel Régional de Camargue, PNR). That proved to be very important in securing a good stewardship of the survey and good conditions for the interviews. Interviews were managed by the authors and by 3 professional surveyors, each having in charge a speci…c area.

The attributes choosen to describe cropping technology should be credible and relevant. Nonetheless, the number of attributes is constrained by the cognitive burden involved in the choice tasks.We thus identi…ed six attributes, assuming they are the main factors explaining the farmers technology choices (Table I below). Three of them are related to agro-ecological means; the length of life cycle of rice cultivar, the weeds control technology and the type of croprotation. Two other concern outcome; the average yield over …ve years and the the yield variability. The …nal attribute is a monetary attribute, representing a compensating payment. Weeds control appears to be one of the main problems in irrigated rice cropping in the area. The technology chosen has implications in terms of workforce, use of herbicides, and impact on the biodiversity and environment. It is therefore important will to de…ne farmers' sensibility about the choices of weed control technology. The practices proposed in the choice sets are currently practised in the area, even if not very widespread, for instance, manual and mechanical weeding. The choice of the rice cultivar, involving the length of the crop' life cycle, is another relevant attribute insofar as it has consequences on production risk. The type of crop rotation on the same plot is constrained by the weed control and by the salinity of the root zone. When the weed control is not good enough, it is necessary to leave rice cropping for wheat or alfa-alfa. But after a few years of wheat cropping, it is necessary to go back to irrigated rice cropping, to ‡ush salt from the root zone 2 .

We used a fractional factorial design to create the experiment structure. An optimal and e¢ cient design is characterized by three properties, orthogonality, balance and minimum overlap [START_REF] Huber | The importance of Utility Balance in E¢ cient Choice Designs[END_REF]. We generated it with SAS R software program, following guidelines by [START_REF] Kuhfeld | Marketing research methods in SAS[END_REF]. The e¢ cient choice task design resulted in 24 choice sets. In order to limit the number of tasks per respondent, we split them in two blocks. Two sets were discarded due to the lack of realism, so each rice grower faced 11 choice sets, each containing three options. We could not introduce a status quo alternative, given that each farmer has a di¤erent business. There were two alternatives and one opt-out option, in which the farmer choose to leave his land unexploited. This later option can provide null or even negative utility (Table II). The main interest of the opt-out option is twofold : not to force respondents to choose an unsatisfactory option, and being relevant, because the fallow is an option in the actual CAP.

The questionnaire was organized in three parts. The …rst one is about the respondent 's personal identity, with some opinion questions concerning their conception of the farmers 'profession, and their sensibility with respect to environmental preoccupations.. The second one is the choice experiment exercise itself, The last part concerns questions about the description of the entreprise, for instance the size, the crops, the crop rotation, the suppliers, the customers, and the presence of marshes...

Starting from a list of 200 farming entities delivering rice to the rice processing industry, the …nal whole population of decision makers has been de…ned as a list of 104 managers involved in the economical and technological decision making process (often, the same manager is in charge of managing several farming units). One would remarks that the list represents the entire population of the decisions maker, and not simply a sample.

Models Estimations

The choice data were analyzed and estimated using LIMDEP 9.0 software program, and more precisely the package NLOGIT 4.0. We have four quantitative attributes (varietal choice, average yield, risk and monetary attribute), and two qualitative (weeds control technology and crop rotation) we have coded using e¤ect coding. For the two scenarios proposed, the rice growers' indirect utility derived from the attributes of our choice experiment study takes this form :

V ij = CV (Zvarietal choice) + RISK(Zrisk) + ROL(Zlong rotation) +ROC(Zcereal rotation) + AEM (Zmanual weeding) +ASM (Zmechanical weeding) + ACHI(Zintensive chemical weeding) +RDT (Zyield) + P RI(Zmargin dif f erential) and the following form for the third alternative, the opt-out one :

V ij = ASC
We introduce here an Alternative Speci…c Constant (ASC) to take into account e¤ects on utility which are not explained by the attributes, and the utility function takes a such form in this option because of the absence of attribute and level to describe it, given it is an opt-out alternative. This is a way to model these situations in choice experiment work. After having estimated a basic multinomial logit model, several others models were estimated to consider …rst the presence of the opt-out option (sample selection model), and then to better integrate the heterogeneity in the rice growers tastes (Random parameter model and latent class model). For qualitative variables, we chose as reference levels those which are the most widespread among the current practices of the rice growers in Camargue. The parameter attributes associated with levels "cereal" rotation, long rotation, mechanical weeding, and those for risk, yield and prime are all signi…cant, at the 1% level of con…dence (except "cereal" rotation, signi…cant at the 5% level of con…dence). We can note that long rotation and mechanical weeding are unfavorable to producers, whereas "cereal" rotation, higher yield and premium bring a greater utility to respondents. The parameter estimate of risk is found to be negative, as expected, that is an increasing risk is associated with a decreasing utility, signifying that farmers are adverse to risk. The ASC of the opt-out option is not signi…cant, that can be explained by the fact that the hypothesis of Independence of Irrelevant alternatives (IIA) is violated, insofar as the choice of this option depends clearly on the two other scenarios proposed to the respondent. The IIA property was tested using the [START_REF] Hausman | Speci…cation Tests for the Multinomial Logit Model[END_REF] test. The results are reported in table IV below. All the information must be included in the estimation, and this is not the case with the MNL model. Moreover, the non signi…cance of attribute levels manual weeding and intensive chemical weeding can be the result of a too big heterogeneity in the population of rice growers for these factors, and can reveal the presence of classes in which the preferences would be di¤erent. For all those reasons the MNL model is de…nitively not appropriate.

The basic multinomial logit model

The sample selection model

The sample selection model is a two step model, in which we …rst estimate a probit model to explain the choice of the opt-out option, and then we use this information to …nd the value of attributes' parameters estimates with a selection. In the probit model, as well as the attributes characterizing the scenarios, we introduce instrumental variables, like the practice of additional recreational activities by the respondent, the presence of cattle or sheeps on the farm and the choice by the producer of the response "stop rice growing" to a question on his reaction to the possibility of a hypothetical ban on the use of chemical weedkillers. The table V presents the …nal results, those of the selection model. , which is becoming here much better 3 . The ASC becomes signi…cant and positive. The attributes "cultivar choice" and "manual weeding" become signi…cant too and negative, as expected. Indeed, it is clearly possible to see the repulsion exerted by the mechanical and manual weeding, which are viewed by the respondents as costly practices, in time and money. The fact that the utility decreases as the length of the life cycle increases is consistent with the risk aversion, because the longer is the life cycle, the more the risk is high 4 . The sign and the signi…cance of attributes parameters related to the crop rotation, risk, yield and prime are still the same. The attribute level intensive chemical weeding is the only one no signi…cant.

Nevertheless, due to the existence of a signi…cant group of farmers practicing organic farming, we decided to estimate two models taking into account this heterogeneity in the population, the random parameter model and then the latent class model.

The random parameter model

In the random parameter models, an assumption over the distribution of each of the random parameter (the density function f ( = ) must be de…ned. In this paper, random parameters are speci…ed to be distributed according to the weibull distribution. The model is still better than the basic MNL one. The manual weeding is now very signi…cant, that proves that this attribute level is indeed heterogeneous among the rice growers population. The attribute related to the length of the life cycle appears now to not be very signi…cant, because it is statistically signi…cant at less than the 90% signi…cance level. But the attribute level intensive chemical weeding is now signi…cant, with a positive in ‡uence on the farmers indirect utility. Nothing is change for the other attributes parameters. As we know that heterogeneity exists in our population, we will thus determine how producers split into classes, and estimate attributes parameters for each of them. That's why a latent class seems to be the most relevant model. The …rst class involves 60 % of the population of decision-makers. Attributes a¤ecting negatively their utility are the long crops rotation, the mechanical weeding and higher risk , whereas higher compensatory premium and yield increase their indirect utility. This class certainly encompasses farmers committed to the technological norms of the PGI (Protected Geographical Indication) "Riz de Camargue". That norm does not exclude the use of chemicals. One could consider that norm as a main or dominant farming subculture. In that class' estimates, several attributes are not statistically signi…cant. This can be either the consequence of the cognitive complexity involved by the management of a high number of attributes, the respondents focusing only on the main attributes they consider relevant for them, or by the direct in ‡uence of the norm on their responses.

The latent class model

Beside that core class 1, there are two opposites classes, one being characterized by the rejection of any agro-ecological practices (one third of the overall population), and the other characterized by their adoption (10%) .

In class 2, all the attributes except the length of the cultivar's life cycle are signi…cant. Crop's rotation including more wheat and intensive chemical weeds control are positively valued, while long rotation, manual or mechanical weeds control are negatively valued. In class 3, the parameter of the length of the cultivar's life cycle is positive and signi…cant, but the attributes characterizing the preferences for the crop's rotation are not. Indeed, manual or mechanical weeds control are valued positively, while intensive chemical weeding is negatively valued. In both classes 2 and 3, the ASC are positive, a result contrasted with the negative ASC in class 1. One could interpret that by the di¤erence in the level of the reserve utility associated to the opt-out choice. In other words, farmers belonging to class 1 exhibit a negative utility of the no production option. Farmers belonging to class 2 or class 3 have each a strong and clear farming subculture, and they prefer to not produce instead of implementing one unwanted technology . These results are in some way surprising, because we have not anticipated the strength of the preferences for an intensive farming system. The remaining question is about the interpretation to be given to that observation. Is it really the expression of a strong farming subculture, or the simple expression of the existence of one strong agro-ecological constraint arising from the presence of salt in the underlying soils layers and aquifer ?

6 Estimation of the "value" of technology' attributes

The monetary value of each attribute, called implicit prices or part-worth, could be calculated from the latent classes estimates, using the following relationship:

Implicit price = attribute = monetary attribute
This implicit price represents the marginal welfare variation for a change in any of the attribute. It corresponds to a compensatory payment that farmer are willing to accept (WTA) for adopting an attribute (or for a one unit improvement in the attribute level), in the case of negative values, or to give it up, in the case of positive values. All the farmers in the three classes attached a positive value to higher yields, whereas a negative value has been always attached to the risk attribute. Only the level of the implicit price for those attributes di¤ers from class 1 and 2 to class 3. Class 3, which is certainly associated to organic farming preferences, exhibits a risk aversion considerably higher than the two others groups.

For all the remaining attributes, preferences are very contrasted from classes 3 to class 1 and 2. For the later, negative values are associated with agroecological practices, while positive one are given to the intensive use of chemicals. For the PGI "Riz de Camargue" producers, mechanical weeds control and long rotation (two characteristics of organic farming) are highly negatively valued. The aversion for the manual weeds control is more moderate, with a lower negative value. However, we can observe in the second class an important rejection of all organic agro-ecological practices, more especially manual and mechanical weeds control, and a strong preference for the intensive chemical weeding. This class represents indeed an intensive farming subculture. Finally, the last class is the one with the highly contrasted values. All attributes related to the weeds control and the risk's level are very important for these rice growers. They have a strong aversion for an intensive use of chemicals, and are willing to practice a manual and mechanical weeds control.

Conclusion

Using a choice experiment survey, this research has elicited rice growers valuation of attributes describing their technology'individual preferences.

With help of experts and after several tests, we identi…ed …ve relevant technology's attributes, three related to agro-ecological means (length of life cycle of rice cultivar, weeds control technology, type of crop-rotation), two related to outcome (average yield and yield variability) and …nally, a sixth monetary attribute, representing a compensating payment in addition of the base gross margin. Choice sets have been proposed to the farmers, including one opt-out options, leaving the land unexploited.

The econometric analysis of the data demonstrated a great heterogeneity in the preferences among the decision-makers in the area. Random parameters logit and Latent Class Models helped to give a more precise view of that underlying heterogeneity.

Facing the cognitive di¢ culty of the task choice, respondents certainly used the references of existing collective norms in the Camargue area as benchmarks. The Latent Class Model identi…ed a core class of responses corresponding to the standard of the PGI "Riz de Camargue", and a little one, corresponding to the "organic farming standard". Nevertheless, beside these well-known standard, an important group of respondents, representing one third of the farmers population, expressed their preferences for a technology using more intensive cropping practices. The question about the interpretation to be given to that observation is still open. Is it really the expression of a strong farming subculture, or the simple expression of the existence of an strong agro-ecological constraint pertaining to the presence of salt in the underlying soils layers and aquifer?

Whatever the interpretation would be, the results are nevertheless worthy for the managers of the collective standards or of the corresponding marketing channels. Moreover, they have a great value for policy makers, because they identi…ed and measured the diversity of values attached to the main components of the rice cropping technology in the area.

Estimates of the implicit prices show that breathing spaces exist to bring rice growers about to adopt environmental friendly practices through market or public policies incentives. It's worth noting that the compensatory payment to give to farmers of class 1, the most important in number, is of the same magnitude as the actual "bulk unconditional payment", the so-called "DPU" . Our results could help in designing targeted contracts by sub-area, conservation or environmental objectives.

ANNEX Empirical data on the surveyed farmers population

General description of the sample

In Camargue area, the rice growers population is almost exclusively male and old, with more than half of farmers being more than …fty years old. Moreover, producers are relatively well educated, in general or with a special education in agriculture. With regard to the education in agriculture, the population split almost equally into those who don't have any particular education in farming, and those who have received one. -produce quality food products 66% -produce raw materials for industry at the lower price 1% -produce quality food products in controling negative impacts on Environment 33% -produce recreational and environmental services 0% "Entrepreneurs in Agriculture" :

-produce quality food products 70% -produce raw materials for industry at the lower price 1% -produce quality food products in controling negative impacts on Environment 29% -produce recreational and environmental services 0% "Multifunctionals Farmers" :

-produce quality food products 64% -produce raw materials for industry at the lower price 0% -produce quality food products in controling negative impacts on Environment 36% -produce recreational and environmental services 0%

Table I :

 I Attributes description and levels

	Table II : example of a choice set
	In the event where the following technical itineraries would be the only you
	face to produce, Which one would you prefer adopt ?
	Attributes options		Description Scenario A	Levels Scenario B	Scenario C
	Weeds control Weeds control	Method of weeds control Fake seeding and manual	1 : intensive chemical weeding (three applica-Lines seeding and me-
	technology		weeding	tions or more), chanical weeding
	technology Crop rotation	"intensive cereal"	2 : chemical weeding with one or two applica-"cereal"
	Varietal choice	Short cycle	tions, Long cycle
	Average	yield	[ 5 ; 7 t [	< 2t	3 : lines seeding and mechanical weeding,
	over …ve years			4 : counterfacted seeding and manual weeds
	Variability=	1 bad year with respect to	removing 1 bad year with respect to
	Cultivar choice risk over …ve	Rice cultivar characterized by the average the average 1 : short cycle : 140-150 days,
	years		a di¤erent length of life cycle 2 : medium cycle : 150-160 days,
	Margin di¤eren-	0 euros / ha	3 : long cycle : > 160 days 1000 euros / ha Leave the land un-
	Crop Rotation' tial	Rice return time on the same	1 : long rotation (1 year of rice /5 years), exploited
	type	plot. It is the number of years 2 : "cereal" rotation (2 years of rice / 5 not A /_ / B /_/ C /_/
					necessarily consecutive years ),
			of rice growing		3 : "intensive cereal " rotation (2 or 3 consec-
					utive years of rice )
	Average yield over	Average of the wheat yield for	1 : < 2 tons,
	…ve years	a …ve years period		2 : [ 2 ; 5 t[,
					3 : [ 5 ; 7 t [,
					4 : 7 t
	Yield variability	Frequency of yields below the	1 : 0 year,
			average		2 : 1 year,
					3 : 3 years
	Compensatory	Extra income o¤ered either	1 : 0 Euro,
	payment	by the market, or by the CAP 2 : 400 Euros / ha,
			over the base margin created	3 : 700 Euros / ha,
			by the scenario		4 : 1000 Euros / ha

Table III :

 III Estimates of the multinomial logit model

	Variable	Value	std error of
	ASC	-0,6942	0,8667
	Cultivar choice	-0,0078	0,0057
	Rotation
	"Cereal"	0,1453**	0,0645
	Long	-0,2491***	0,0697
	Weeds control technology
	Manual	-0,1135	0,0735
	Mechanical	-0,4751***	0,0777
	Intensive chemical	0,1146	0,0787
	Risk	-0,1983***	0,0442
	Yield	0,0226***	0,0019
	Prime	0,0011***	0,0001
	Number of observations	1144
	Number of parameters	10
	Log likelihood	-1154,521
	Rho-squared	0,14347
	*, **, *** means statistically signi…cant at 90%, 95% and 99% signi…cance level

Table IV :

 IV IIA test

	Alternative dropped	2	Degree of freedom Probability
	Scenario A	28,0554	10	0,001769
	Scenario B	19,3113	10	0,036482

Table V :

 V Estimates of the sample selection model

	Variable	Value	std error of
	ASC	0,6679***	0,0406
	Cultivar choice	-0,0040***	0,0003
	Rotation
	"Cereal"	0,0297**	0,0142
	Long	-0,0539***	0,0142
	Weeds control technology
	Manual	-0,0308*	0,0159
	Mechanical	-0,0815***	0,0165
	Intensive chemical	0,0175	0,0173
	Risk	-0,0201**	0,0086
	Yield	0,0052***	0,0004
	Prime	0,0003 ***	0,0000
	Number of observations	2415
	Log likelihood	-1411,562
	Log likelihood (restricted) -1730,990
	Rho-squared	0,22893
	Chi-squared	638,86
	signi…cance level	0,0000
	*, **, *** means statistically signi…cant at 90%, 95% and 99% signi…cance level
	We can note that more variables are signi…cant, and the global model is
	better, in terms of McFadden

  2

Table VI :

 VI Estimates of the random parameter model

	Variable	Value	std error of
		Random Parameters
	ASC	0,4957	1,6382
	Manual weeding control	-2,1191***	0,5925
	Non Random Parameters
	Cultivar choice	-0,0114	0,0071
	Rotation
	"Cereal"	0,2291**	0,0923
	Long	-0,4297***	0,1216
	Weeds control technology
	Mechanical	-0,4755***	0,0992
	Intensive chemical	0,1895*	0,1023
	Risk	-0,2079***	0,0626
	Yield	0,0312***	0,0043
	Prime	0,0015***	0,0002
	Number of observations	1144
	Log likelihood	-1154,5208
	Log likelihood (restricted) -1256,8125
	Pseudo rho-squared	0,21752
	Chi-squared	546,7686
	signi…cance level	0,0000
	*, **, *** means statistically signi…cant at 90%, 95% and 99% signi…cance level

Table VII :

 VII Estimates of the latent class model

	Variable	Class 1	Class 2	Class 3
	ASC	-2,5141**	3,5569**	5,3621**
	Varietal choice	-0,0074	0,0095	0,0183
	rotation
	"Cereal"	0,1235	0,2156**	0,2093
	Long	-0,3509*** -0,3318***	0,5052*
	Weeds control technology
	Manual	-0,0157	-0,7728***	1,5897***
	Mechanical	-0,5397*** -0,8994***	1,3060***
	intensive chemical	0,0424	0,7935*** -1,1725***
	Risk	-0,1963*** -0,3139*** -1,0818***
	Yield	0,0238***	0,0221***	0,0577***
	Prime	0,0010***	0,0018***	0,0010*
	Probability of class	0,6014	0,296	0,100
	Number of observations	1144
	Log likelihood	-1154,521
	Log likelihood (restricted) -1256,812
	Pseudo Rho-squared	0,3089
	Chi-squared	776,3506
	signi…cance level	0,0000000
	*, **, *** means statistically signi…cant at 90%, 95% and 99% signi…cance level

Table VIII :

 VIII Technology'attributes implicit prices (in Euros)

	Variables	Class 1	Class 2	Class 3
	Cultivar
	rotation
	"Cereal"		119,11
	Long	-337,39	183,34	510,29
	weeds control technology
	Manual		-426,99	1605,78
	Mechanical	-518,99 -496,92	1317,14
	Intensive chemical	40,81	438,42	-1184,31
	Risk	-188,74 -173,41 -1092,74
	Yield	22,89	12,23	58,27

Table I :

 I Socio demographic characteristics of the decision makersThe rice growing farms in Camargue have usually broadacre (more than 100 ha), and in particular the majority of them are bigger than 200 ha. Only a low percentage (2,5%) of exploitations are very little, that is a net farming area below 50 ha.

	Characteristics	Frequency
	Age :
	-18-35 years	14%
	-36-50 years	33%
	-More than 50 years	53%
	Sexe :
	-Male	98%
	-Female	2%
	General education :
	-No general education	10%
	-Primary education	14%
	-Short secondary education	31%
	-Long secondary education	23%
	-Higher education	22%
	Education in Agriculture:
	-No agricultural education	41%
	-Primary education	2%
	-Short secondary education	16%
	-Long secondary education	12%
	-Higher education	29%

Table II :

 II Characteristics of farmsTable III : The farming subcultures among the rice growers According to you, the farmer profession consists to : Frequency Overall population :

This research is co-funded by the two Regional Government of Provence-Côte d'Azur and of Languedoc -Roussillon

We are grateful to J.C. Mouret (INRA, UMR Innovation) and to C. Thomas (CFR) for their helpful advices and comments. Final choice of attributes remains our responsability

According to[START_REF] Hensher | Applied Discrete Choice Modelling[END_REF] 2 values between 0; 2 to 0;

are consider to be extremely good …ts.[START_REF] Bougherara | Farmers'Preferences over Conservation Contract Flexibility and Duration, An Estimation of the E¤ects of Transactions Costs using Choice Experiment[END_REF] A seed with a long life cycle forces the rice growers to sow earlier, and thus it can be risky if the weather is cold during the fertilization, that causes a bad rice rising.

Characteristics

Frequency Net farming area :

-< 50 ha 2,5% -[50-100 ha[ 23,5% -[100 ha-200 ha[ 31% ->= 200 ha 43% Organic cropping :

-A part of the whole surfaces in organic 22% -All surfaces in organic 15%

A typology of rice growers with farming subcultures

We elaborated a typology of the decision makers with respect to the farm's characteristics and to personal conceptions of the profession.

Due to the importance of recreational activities in the Camargue area , we focused on the presence on the farm of pertinent criterion such as additional recreational activities (tourism, commercial hunting, bull race...), marshes (and more precisely swamps for hunting), cattle (belonging to the farm or not), and then we included also the average crop's yields.

We …nally identi…ed two main groups:

-the …rst one encompasses rice growers who focused only on the farming production. We call them "Entrepreneurs in agriculture" given that they have a "productivist"farming subculture and get highest yields. Indeed, only few of them (7%) are concerned by very lower yields ([2t-5t[). They don't manage any additional recreation activities nor natural spaces (no land for cattle or marsh). They represent 40% of the whole population.

-the second one encompasses "Multifunctionals Farmers"who integrate natural area into their management, while their conception of farming takes into account ecological considerations. They combine agricultural production, recreational activities, and manage cattle and marshes. A great part of them get agricultural yields in the range [5t-7t[, but with a greater dispersion than the "Entrepreneurs in Agriculture". They represent 60% of the population.

To complete this general presentation, we end up with linking the former typology to the personal conceptions about the farming profession. That resulted in the de…nition of two farming subcultures (Table III).


Extended summary

Much work has been done in economics to appraise consumers' environmental characteristics valuations. Economists have employed several methods to determine how consumers value the environmental characteristics of foodstuffs.

In this study, we used an experimental market to determine consumer's willingness to pay (WTP) for produce grown with different pesticide levels. We worked on apples grown with different production types: conventional apples, Integrated Pest Management (IPM) apples and organic apples. Experimental markets are carried out in Portugal, France (for the period May 2008 to October 2009) and then in Greece and Holland (2010).

The pesticides use complies with legal norm in the conventional apple. The pesticide quantity use is lower in the IPM apples and there is no synthesis pesticide in the organic apple.

In this experimental market, we evaluated the consumers' WTP under different information conditions.

There is a consumer willingness to pay higher for produces grown with less pesticides and the preferred certification is the zero synthesis pesticides (i.e. organic produce). We show the following results. i) In Portugal, the premium against a regular product is 53.6 % for Integrated Pest Management (IPM) and 96.4% for organic products. ii) In France the premium is 43.6% for IPM and 72.5% for organic products. However, in both two countries, premium increase is lower for a processed product.

Introduction Survey of the literature about experimental economic methods and consumer's willingness to pay (WTP) for pesticides reduction

The first works regarding consumer's WTP for pesticide reduction have used stated preferences methods. Their goal was to estimate the consumers' perception of risk associated with pesticides use. [START_REF] Hammitt | Risk Perceptions and Food Choice: An Exploratory Analysis of Organic-Versus Conventional-Produce Buyers[END_REF] focused on organic products by comparing them with the conventional ones.

Consumer's choices show that they were willing to pay significant premium to obtain the organic product (a median 50% above the cost of conventional produce). [START_REF] Misra | Consumer Willingness to Pay for Pesticide-Free Fresh Produce[END_REF] used a survey sent to 580 households in the Georgia in order to determine consumers' perceptions of food safety and their attitudes toward pesticides use. At the question 'Are you willing to pay a higher price for certified residue free produce?', 46% of the participants answered 'yes', 26% answered 'no' and 29% are not sure. Among those who were willing to pay a premium, 87% were willing to pay a maximum of only 10% more for certified residue free produce.

Eom 's study (1994) also used a survey to estimate consumers' preferences toward health risks posed by pesticide residues. The author collected 567 questionnaires from interviewers at grocery entrance in North Carolina. In the survey, the author compared produces commercially grown with pesticides and produces screened for pesticide residues. He found that consumers were willing to pay substantially high price premiums for safer produce: 65% of respondents were willing to pay on average $0.35 ±0.57 per pound more for the produces screened for pesticide residues.

Baker (1999) used a conjoint analysis to evaluate consumer responses to hypothetical apple products in a nationwide survey sent to households in the US. The author worked on 510 surveys. One of the aims of the study was to try to understand consumers' valuation of food safety attributes. Product characteristics included price, quality, pesticides use levels and the corresponding cancer risk and type of government inspection. Consumers expressed a broad preference for reduced pesticides use.

With their study, [START_REF] Mourato | Evaluating Health and Environmental Impact of Pesticide Use: Implication for the Design of Ecolabels and Pesticides Taxes[END_REF] estimated the economic impacts of pesticide use on human health and on the environment. For that, they estimated consumers' WTP thanks to a contingent ranking approach, which is a survey based technique. Questions have been asked

to 504 UK participants. It was a survey with questions concerning the environmental impacts of pesticides use on wheat production. The results suggested that consumers would be willing to pay substantial price markups for environmentally friendly bread loaves: an average of 0.7 pence per loaf of bread to avoid case of human illness.

Using a double-bounded logit model, Loureiro et al. (2002) wanted to assess the mean WTP for eco-labelled apples. They concluded that female respondents with children and strong environmental and food safety concerns were more likely to pay a premium for eco-labelled apples. However the estimated premium was small (about 5 cents per pound over an initial price of 99 cents), reflecting the overall difficulty with garnering a premium based on "environmentally sound" practices. [START_REF] Cranfield | Canadian Consumer's Willingness-To-Pay For Pesticide Free Food Products: An Ordered Probit Analysis[END_REF] undertook a contingent valuation survey to determine if Canadian consumers would pay a premium Pesticide Free Production. Pesticide Free Production is a production system that falls between organic and IPM agricultural production. Authors worked on 295 surveys from participants from Calgary, Toronto and Winnipeg. They found that 67% of respondents would be willing to pay a modest (i.e. 1 to 10%) premium for Pesticide Free Production relative to a conventional produce and that about 5% would pay a 20% premium. [START_REF] Chalak | Pesticides, preference heterogeneity and environmental taxes[END_REF] presented results from two choices experiments designed to take account of the different negative externalities associated with pesticide use in agricultural: reduction of environmental quality or problem on consumer's health. The results showed that there is preference heterogeneity in addition to a reasonably high WTP estimates for a reduction in the pesticides use for both environmental quality and consumer health.

Mainly, the studies presented in the former section have concluded that there is a premium for the environmental characteristics of food. But all these studies have recorded behavioural intentions which may not completely correspond to actual behaviour in market transactions. [START_REF] Loureiro | Are Stated Preferences Good Predictors of Market Behavior[END_REF] showed that consumers who stated that they are willing to pay a premium, which is equal to or greater than a positive lower bound, had a higher likelihood of actually buying the product in question. This implies that consumers' actions in the economic experiment validate their survey responses.

Thus, it is necessary to use methodologies that are not only based on consumers' statements but that analyse their real buying behaviour: the experimental economic approach.

Experimental economics methods put people in an active market environment dealing with real money and real products. This valuation provides, in a direct form, a set of heterogeneous WTP that in theory represent the real value for the products.

In the experimental economic approach, individuals are in a laboratory environment with a simplified economical situation reproduced. Smith (1980) and List (2006) showed that laboratory behaviour is a good indicator of field behaviour. [START_REF] Roosen | Consumers' valuation of insecticide use restrictions: An application to apples[END_REF] were the first to analyse WTP for pesticide-free produce in experimental economics. They recruited 54 American participants and used the Vickrey's auction method to determine the consumers' WTP. Their analysis showed that WTP for produce free from neuroactive pesticides is significantly higher than for conventional produce and that the inferior appearance of the apples has a significant (negative: -63%) effect on WTP. The authors measured also consumers' WTP for a partial reduction of pesticides use in apples.

They found a 50% increase of WTP between the partial pesticides reduction and the complete pesticides lack. Bougherara (2003) evaluated consumers' WTP for 3 different kinds of orange juices: standard, organically-farmed and environmentally-friendly. The participants were divided into two groups. In the first group, participants had to reveal their WTP by the BDM procedure before and after receiving information about the meaning of organically-farmed and environmentally-friendly. In the second group, participants had to reveal their WTP just once after reading information. With this study, Bougherara showed that revealing information about healthy risks did not affect the valuation of the labelled product but did cause a loss of value for the conventional product.

This result about negative impact of information on non-labelled product was also shown by [START_REF] Combris | Does Taste beat Food Safety? Evidence from the "Pera Rocha" case in Portugal[END_REF] with an experiment on pears. They used the BDM procedure on 74 participants who had to give their WTP under different information conditions of 3 kinds of pear: conventional, retailer quality, Protected Denomination of Origin. These pears were presented with different signals. The results showed an important decrease of WTP for pear without signal.

Another study shows the same results: [START_REF] Rozan | Willingness to Pay for Food Safety: an Experimental Investigation of Quality Certification on Bidding Behaviour[END_REF] worked with 120 consumers aged from 20 to 65 and with 3 types of products (apples, potatoes and bread) available as certified or non-certified. The two procedures used were BDM mechanism and the second price auction mechanism. They observed that buying prices for non certified food products decrease when healthy information (controlled heavy metal content label) is provided. However the buying prices for certified products did not significantly increase.

Experimental markets

The experimental markets design, described below, was defined.

The aim of this experiment was to measure the consumers' willingness to pay (WTP) for apples and for a processed product (apple juice) produced with less pesticide.

In this study we also wanted to compare two different methods to obtain the WTP: one direct method (direct sales with different prices with the Becker-DeGroot-Marschak (BDM)

procedure 1 and an indirect method (choices between different size's lots of the preferred apple and any other apples). Another aim was to see if the potential diversity in consumer behaviour was depending on geographical location.

The markets included both fresh products (apples from the two varieties Royal Gala and Granny Smith for Portugal's experience and Golden for the France's experience) and processed ones (apple juice).

In order to see the impact of different information about pesticides use, we used different apple types which are product with different level of pesticides:

-Regular apples, -Integrated Pest Management (IPM) apples, -Organic apples.

The regular apples correspond simply to the respect of the national legislation for the pesticides' use. The IPM apples correspond to a controlled reduction of these pesticides as compared to the existing legislation; this is a well known concept which leads to reduce pesticides on farms. However, this concept is quite complex and does not clearly define a list of banned pesticides or even a maximum use level for pesticide. The organic apples correspond to a total lack of the synthesis pesticides in the context of organic farming.

1 Becker, G., DeGroot, M., Marschak, J. (1964). "Measuring Utility by a Single-Response Sequential Method".

Behavioural Science, 9: 226-232.

We also wanted to know the impact of pesticides reduction on a processed product: the apple juice. We used the same level of reduction for the apple juice:

-Regular juice = juice obtained from regular apples, -IPM juice = juice obtained from IPM apples, -Organic juice = juice obtained from organic apples.

Apples were presented to the consumer with their labels (or without in the case of the regular apples which did not have any label).

We used different apples types in Portugal and in France. In the case of the Portuguese experience, we were careful to take into account the heterogeneity of tastes that can be observed in this market. For that, we asked to the consumers to make an advance tasting of two varieties: type "tart" with the Granny Smith variety and type "sweet" with the Royal Gala variety. These precautions made it possible, not only to limit the number of systematic refusals to purchase during the experiment, but also to prevent having consumers that proposed a purchase price equal to zero in whatever the selling situation. In France, we proceed a bit differently. Thanks to the Portugal's results, we knew that around half of the participants would take the "tart" type apples (Granny Smith) and that the other half would take the other type: Royal Gala and particularly, we knew that no consumer was really against one type. So we decided to use only one variety but a quite common variety. We decided to work with the Golden variety, which is the most consumed type in France. Furthermore, to avoid any problem, we asked to all the participants which type of apple they usually consume and recruited only the one who answered at least the Golden type. The other difference is the size of the apple. In Portugal, all the apples had the same calibre although in France, calibres were a bit different: the organic apple was a bit smaller than the other. So we had to add one small apple in order to not have just one small apple in the French experiments.

In both countries, the experiment included three stages:

Stage 1. Sales of apples

The objective of this stage was to measure consumers' WTP for pesticide reduction and to show how the results depended, or not, on a modification both of the intrinsic characteristics of the products (variety of apple, organoleptic quality, size, etc) and also of the extrinsic aspects (brand and origin of products). Thus, we showed how an eventual increasing of the WTP, due to pesticide reduction, was conditioned by the stability of the organoleptic properties. This is an important result when it comes to discuss how much the producers should reduce the pesticide level regarding the potential gain that can be obtained through a reinforcement of taste.

In Portugal, a lot of technical specifications regarding the characteristics of products were also measured in order to know their relevant characteristics ("Brix", acidity) and to estimate the correlation between WTP and these characteristics. With these measurements, we saw that the WTP is perfectly correlated to the hedonic note. We also saw that for the Royal Gala (variety with more sugar than the Granny Smith the WTP is positively correlated to the "Brix" and the WTP is negatively correlated to the pH and that this is the opposite for the Granny Smith. So, because we had already these answers, we didn't do all the physicochemical measures in Dijon.

Stage 2. Sales of apple juice

The aim was to measure how the consumer response might be different according to the reduction of pesticides in the processed material. The changes verified in the WTP were then compared with those obtained previously with apples sales on stage 1.

Note that for stage 1 and stage 2, the value elicitation mechanism used was the Becker-DeGroot-Marschak mechanism.

Stage 3. Choice of apple lots

This stage assessed the robustness of the results obtained in comparing them to a situation of exchange (valuation of the Willingness to Exchange, WTE). The principle was the following.

Based on the results obtained in stage 1 of the experiment, it was possible to identify the preferred alternative of each consumer. Each participant was then informed that this new stage consisted in making choices between different quantities (in Portugal) or weight (in France, because of the size differences) of apples of their preferred apple and the other apples.

The results obtained under these hypothetical trades allowed us to reconstitute the WTP of each consumer for the various certifications proposed. Thus, it was possible to measure the robustness of the WTP obtained in stage 1 of the experimentation.

Principal results

The results show that there is a premium for a pesticide use reduction: consumers agreed to pay more for product safer for them but they prefer a total lack than a partial reduction because they are ready to pay more for organic produce after they received the information on the zero synthesis pesticide use than for the IPM produce. We show the following results. i) In

Portugal, the premium against a regular product is 53.6 % for Integrated Pest Management (IPM) and 96.4% for organic products. ii) In France the premium is 43.6% for IPM and 72.5% for organic products. However, in both two countries, premium increase is lower for a processed product. We also underlined the importance of the taste in consumers' choices because they decrease their WTP after tasting the product they didn't like in the blind tasting.

Protocols presentation

The aim of these experiments was the same in the two countries. After the first experiment in Lisbon, we changed a little bit the protocol for Dijon in order to improve this protocol according to Lisbon's results. That's why there are few differences between the two protocols.

Participants and session

The experimental protocol design was first applied in Portugal, in Lisbon, to 102 consumers and then in France, in Dijon, to 107 consumers.

In Lisbon, the experiments took place in the Agronomic University building. In Dijon, we worked in the INRA's sensory analysis room; INRA is the National Institute of Agronomic Research.

We did 11 sessions in Lisbon and 10 in Dijon (because the room was bigger in Dijon: we were able to receive 10 people maximum in Lisbon and 16 people maximum in Dijon). The session lasted around 1h30; it was at 2.30pm, 6pm and 8.30pm in Lisbon and at 3pm and 6pm in Dijon.

The recruitment

Participants were randomly recruited from the general population, according to a set of criteria, specific to this type of experience. For the recruitment, the same questions have been asked to the participants in Lisbon and in Dijon in order to have the same information about the consumers. The questions asked were about: i) apples consumption frequency; ii) participant's role in the food shopping in the family; knowledge about apples prices.

We have especially assured that the participants were regular buyers of apples (at least once a week). If the answers met the criteria, i.e. the frequency consumption was at least once a week, participant was doing the shopping sometimes (at least once every two months) and the answer to the price they think for 1kg of apple was less than 5€ , we asked for all the sociodemographic data.

All the consumers recruited received a letter with explanation about the experiments but there were nothing said about pesticides. In this letter, it was explain that the subject of the study was the valuation of apples coming from different types of production.

Experimental procedure

As we said above, we used different certifications: the regular apple, the IPM apple and the organic apple. The IPM certification can be guaranteed by the producers, by the retailer or by producers from a specific area. To see if there is an impact of the guarantee's origin we used different apples from each certification. The different apples were distinguished by their labels. The producers' IPM apples were defined as 'Protecção Integrada' in Portugal and as 'Production Fruitière Intégrée' in France.

As we said above, there were 3 stages in the protocol: apples sales, apple juices sales and choices between sets of different types of apple.

At the end, there were the drawing lots. This part has been done to involve the participants properly in the experience; this is a proper part of the BDM mechanism. Because they are liable to buy one product, the participants are supposed to be more precise in their answers.

A. Stage 1 (sales of apples)

In this first stage, there were four steps and in all steps, consumers had to answer to the same question: "What is the maximum price you are ready to pay to buy 1kg of this apple?" but with different information.

-1 st step = intrinsic characteristics At this step, the consumers did not have any information about the apples. This was a 'blind tasting'. The only information was the name of the variety because the participants can know it just by looking at the product. After the evaluation, the participants gave the maximum price they were ready to pay for 1kg of each apple they had tasted.

There was a difference between Portugal's and French's experiments for this step. In Lisbon, the participants had to taste six apples from two different varieties: three Granny Smith and three Royal Gala. In the two varieties, there was: one regular apple, one IPM apple and one organic apple.

In Dijon, the participants had to taste six apples from the same variety (the Golden variety).

Apples were evaluated three by three, it means variety by variety in Lisbon and all the six simultaneously in Dijon.

In this step and only for Portugal, the participants had to answer to a sensory analysis questionnaire: colour, texture, flavour and global taste.

At the end of this step, each consumer has given a maximum purchase price for six different apples.

In France, the whole experiment was carried on using only the Golden variety. In Portugal, it was different. For each Portuguese participant, the prices' mean for the three apples for each variety has been calculated in order to find the preferred variety. If there were two equal means, the variety with the apple with the higher price was chosen. And in case of equality between the two first prices, the variety with the third higher price was chosen and so on.

Only the preferred variety (Granny Smith or Royal Gala) was then used for the next steps.

-2 nd step = extrinsic characteristics without information Then, in Lisbon, participant had to taste different apples from their preferred variety: regular apple, IPM apple and organic apple. They had to taste different Golden in France: the same one and one small regular apple.

Apples were presented simultaneously to the participants with their labels. No information was given to the participant and they were not allowed to taste the products. They were asked to evaluate the apple in looking at, in touching at, in smelling at but without eating it and to answer to the question: "What is the maximum price you are ready to pay to buy 1kg of this apple?"

Note that at the end of this step, in Dijon, participants had to answer to few questions about their knowledge on labels used in the experiment. The question was: "For all the apples you had evaluated, which guarantee do you think you have: a taste guarantee, an area origin guarantee, a pesticide reduction use guarantee?" -3 rd step = extrinsic characteristics with information At this step, each participant received an information sheet with the information about the label they were seeing on the apples. The participants had to read the information sheet and then answer to the same question as before: "What is the maximum price you are ready to pay to buy 1kg of this apple?" At this step they were still evaluating apples without tasting them.

The information given to the participants were a bit different in Lisbon and in Dijon. For the regular apples, the information given was that the pesticides quantities used were following the legal instructions. In the case of IPM apples, we had simplified the information given to consumers, stating that it was a halving of the number and amounts of pesticides used in relation to the benchmark of the regular apple in Portugal and that it was a diminution (without any precision of the diminution's proportion) in France. We specified to the consumers that the reduction was certified by the producers. For the retailer quality apples, we said to the consumers that there was a reduction of the pesticides use and that this reduction was certified by the retailer. In the case of organic apples, consumers were informed of the synthesis pesticides use lack.

-4 th step = intrinsic and extrinsic characteristics with all information

Participants still had the five (Portugal) or six (France) apples in front of them. Now they had to taste the apples before giving their purchase prices in answering to the same question:

"What is the maximum price you are ready to pay to buy 1kg of this apple?"

After this 4 th step, the highest price was spotted to define the preferred certification for each participant. This preferred certification was the reference for the choices in stage 3. In case of equality the preferred certification was chosen by drawing lots.

B. Stage 2 (sales of apple juices)

The principle was exactly the same than the method which was used in the apple sales: BDM mechanism. The difference was that the participants did not have the product in front of them to make the valuation but only the labels of the products. They had to answer to the following question: "What is the maximum price you are ready to pay to buy 1 Litre of this apple juice?" in looking at the 3 labels they had in their hands.

The different juices were issued of different apples: one regular apple juice coming from regular apples, one IPM apple juice coming from IPM apples and one organic apple juice coming from organic apples.

Stage 3 (choices)

For this stage, we used the preferred certification defined at the end of the 4 th step of the apples sales. The participants had all the information, they had the apples still on their table and they were allowed to taste the fruits again. In this part, each participant had to make choices:

-between 1 fixed set (6 units in Lisbon and 1kg in Dijon) of his preferred certification and increasing sets of all the other certifications, -and then between decreasing sets of his preferred certification and 1 fixed set (6 units in Lisbon and 1kg in Dijon) of all the other certifications.

The difference between Lisbon and Dijon was due to the difference of apples size in Dijon. It was not possible to propose unit set in Dijon because, for instance, 6 regular apples are not similar in term of quantities to 6 organic apples. That is why we used quantities set in Lisbon and weight set in Dijon.

Each participant had to complete 8 choice boards in Lisbon (because of the 5 different certifications) and 10 choice boards in Dijon (because of the 6 different certifications):

Boards are like the one below:

-4 like the one below in Portugal: Finally, each participant drew lots for a sales or a choices situation. This drawing lot at the end was explained to the participants at the beginning to involve them. They knew that they were a possibility for them to buy a product at the end of the session.

At this stage, there were two possibilities: i) One sales situation was drawn lots: then the participant was drawing lots for a sale price. If this price was lower than the one he gave during the experience, the participant bought the product at the sale price (i.e. the less expensive). At the opposite, if the sale price was higher than the one given during the experience, the participant didn't buy the product.

ii) One choice situation was drawn lots: the participant had to draw lots for one of the 48 lines in Lisbon and for one of the 60 lines in Dijon of the boards and received the apple set he had chosen on this line.

Results

WTPs' Distribution

Lisbon: Dijon:

The Willingness to Pay's distributions are in accord with a classic price distribution. The zero's answers proportions are not too high and are similar in Portugal and in France: 8% in Portugal and 7% in France.

Sensory data

The WTP is a good indicator to the consumers' preferences: there is a positive correlation really significant between the WTP and the hedonic score for the apples (p<0.001 for the two varieties Royal Gala and Granny).

We notice that consumers are sensitive to the sugar contained in the apple: there is a positive correlation between the sugar contains and the WTP but this correlation is more significant for the Royal Gala variety (p<0.05) than for the Granny variety (p<0.1).

There is also a bound between the acidity rate and the WTP for the Granny variety (p<0.05) but there is nothing between these two data in the Royal Gala variety. This can be explained by the fact that the acidity is expected for the Granny apples but not for the Royal Gala apples.

Policy recommendations

We showed in this deliverable that there is a consumer willingness to pay higher for produces grown with less pesticides and the preferred certification is the zero synthesis pesticides (i.e. organic produce). We showed that the premium against a regular product is more than 40 % for Integrated Pest Management (IPM) in the different countries and 70% for organic products. Even if premium increase is lower for a processed product, it seems, the results that we have obtained, with the experimental market confirm that it is possible to assess the alternatives for having consumers contribute to the improvement of environmental practices.

By using different methods of evaluating the behaviour of consumers, we have shown that the standard evaluation of WTP was a good way to measure consumer demand for pesticide reduction. Nevertheless, this WTP is actually enhanced if the information is passed on to consumers. Hence we showed the need to use the logos of IPM certifications (public certifications or private certifications) and organic production.

Quantity of apple of the preferred certification Quantity of apple of other certification

		Quantity of apple of the	Quantity of apple of
		preferred certification	other certification
		1 kg	1 kg
		1 kg	1.150 kg
		1 kg	1.300 kg
		1 kg	1.450 kg
		1 kg	1.600 kg
		1 kg	1.750 kg
	-	5 others like the one below in France :
		Quantity of apple of the	Quantity of apple of
		preferred certification	other certification
		1 kg	1 kg
		0.850 kg	1 kg
		0.700 kg	1 kg
		0.550 kg	1 kg
		0.400 kg	1 kg
		0.250 kg	1 kg
		6	6
		6	7
		6	8
		6	9
		6	10
		6	11
	-4 like the one below in Portugal:
		Quantity of apple of the	Quantity of apple of
		preferred certification	other certification
		6	6
		5	6
		4	6
		3	6
		2	6
		1	6

Consumer's WTP for pesticides reduction

With this experimental market, we noticed that consumers are willing to pay more for produce grown with fewer pesticides. Indeed, there is a significant difference between regular apples, IPM apples and organic apples after we gave information about pesticides reductions.

Consumers are ready to pay 0.56€ in mean for regular apples, 0.86€ in mean for IMP apples and 1.10€ in mean for organic apples in Portugal. In France, in the same order, means are:

1.01€, 1.45€ and 1.57€. If we speak in term of premium, i.e. each WTP minus regular apples' WTP, the premium for a total lack of pesticides' use is more important than the one for a 50% pesticides reduction: This result is also found with the processed produce: the apple juice. Even if the differences are less important, the premium increases with the percentage of pesticide reduction: At this stage, this is important to note that this premium is dependant of the sensory attributes.

We noticed that because of the differences in consumers' answers before and after tasting.

Indeed, there is a decrease after tasting for the organic apple (before tasting the premium is 96.4% and after tasting this 52.5% in Lisbon and 72.5% before, 59.1% after tasting in Dijon) ; this apple was not really good noted at the first tasting (blind tasting) so its score decreases at the end. At the opposite, the IPM apple which was appreciated during the blind tasting in

France has an increase of its WTP after tasting at the end (43.6% and then 87.7%).

So even if there is a positive message to the consumers like a pesticides use reduction, produce have to be tasty to be purchased at a higher price.


domain: sdv sde shs

text:
Marie-Béatrice Galan

Claudie Pavis

Harry Ozier-Lafontaine

Pierre Bouteiller

Starting a sustainable partnership between the forces of development and research in French Guyana

Introduction

In the 1970s and the 1980s the French agronomic research institutes (INRA) used to support the farmers of the "Plan Vert" (Vissac 1990). But they have gradually withdrawn from the agricultural problematics of French Guyana. As a matter of fact, the partners of agricultural development are now facing multiple problems: increase in the food demand of the population, poor organization and fragility of the different sectors, difficulties in management of soil fertility and phytosanitary problems, lack of technical skills of the majority of the farmers. Therefore, the Chamber of Agriculture of Guyana appealed to the INRA Center of the West-Indies and Guyana (INRA AG) in 2005 to relaunch partnerships and facilitate the emergence of innovations. After several missions of researchers from the INRA AG, and in spite of the critical situation the Chamber of Agriculture, the Guyanese agricultural, institutional and professional partners (Regional Council, DAF,…) and the INRA AG all together appointed "AMBRE Développement" research consultancy in June 2009, in order to take an inventory of the needs and set up a sustainable partnership between research and development.

The main prospects of the study were to define the requirements of an interface device in research and development, as well as the priority actions to be led within the scope of this device. After a presentation of the methodology implemented (analysis of the agricultural Guyanese background, making-up of thematic working groups), we will set out the actions we consider doing within the limits of a partnership based on the choice of organizational devices and schemes to be conducted jointly.

Methodology

A three-phase setting-up of the partnership.

1) Achieving an inventory of the farmers organisations, farmers production systems and extended technical services:

This analysis allows us to assess the feasibility of the partnership. It rests on bibliographical data and interviews of representatives of the different agricultural partners ( public services, local communities, farmers' economic interest groups, associations and cooperatives), technicians and farmers.

2) Building-up working communities composed of development agents and researchers:

Following the interviews, three working groups composed of researchers, agricultural development agents and farmers were formed to consider the next farming systems:

horticultural systems (three meetings), -cattle breeding systems (two meetings), -slash-and-burn or clear cut land farming (two meetings). The purpose of those groups [START_REF] Roybin | Conduite de recherches pluridisciplinaires et apprentissages collectifs[END_REF] was to identify the requests of the professionals, reformulate them and co-create solutions while enhancing the research acquisitions.

3) Setting-up the profession requests and projects transfer within these working communities:

The function of the partnership in Guyana stands out from the usual purpose of research in partnership as generally described, which consists in strengthening the adequacy between the questions of development and research programs [START_REF] Roybin | Conduite de recherches pluridisciplinaires et apprentissages collectifs[END_REF][START_REF] Soulard | La recherche en partenariat : entre fiction et friction[END_REF]. In this case, it is no longer a matter of building research programs but setting up schemes aiming at meeting the demand of the farmers by emphasizing the results of earlier research acquired in different contexts. Therefore, it is a question of projects transfer even if the actualization often requires the implementation of further diagnosis, and experiments which may fall within research. Such improvement aiming at being operational in new contexts can generate new knowledge, and result in scientific developments (Agro-Transfert Picardie, 2006). Consequently, this partnership will focus on the co-construction of the demand, the development conditions, the transfer of knowledge and the expected results of the scheme. To facilitate this co-construction, the meetings of the working groups are conducted by an engeneer in reseach and development who takes an inventory of the questions, informs on the present state of knowledge and research work, and contributes to the construction and formalization of a common work schedule. This mediator helps to "manage the distance between the problems encountered by the practitioners who intend to work on a situation or remedy it, and the aims of the researchers more specialized in the understanding of phenomena and their theoretical formalization" (Fleury et al, 2000).

Results and discussions

Two types of actions came out of the working groups discussions:

1) Actions aiming at strenthening the technical backing operation set up in Guyana:

1-1) creation of an online documentary basis allowing the centralization of the whole technical knowledge about the Guyanese productions ( reports, technical data, tests synthesis, etc…); 1-2) creation of a regional technical group, working on the horticulture problematics, aiming at sharing information and knowledge, mutualizing the means in order to organize training and technical support sessions.

2) Transfer projects chosen according to the following criteria :

themes which raise interest and receive general approval within a group representative of professionals, -attendance of advisers and technicians who maintain the circulation of the results among the farmers, -available research work on the given theme, -identification of researchers who are likely to take part in the project as experts or intermediaries next to research teams whose works are actualized.

2-1) Conceiving innovating means to fight against the bacterial wilt in horticultural cropping systems:

One of the major brake upon the tomato culture in the open ground in Guyana is the bacterial wilt, due to the bacteria Rastoria solanacearum. This illness, against which no efficient chemical treatment has been found, can also affect plants belonging to the Cucurbitacae. The CIRAD Martinique is currently testing the effects of about twenty experimental plants on the development of the bacteria so as to propose an agro-ecological management of the illness. This project is intended to adapt and test the methods proposed in the West-Indies, after having completed a diagnosis of the infestation and the practices of the Guyanese farmers.

2-2) Conceiving production systems intended to meet the expectations of the small farmers practicing slash-and-burn farming ( The Guyanese clear cut land 'abattis'): Slightly more than 4700 out of 5300 farmers practice slash-and-burn agriculture. The demographic pressure and the constraints linked to the infrastrures development have lead the producers to reduce the time required by the practice of fallowing land after 4 or 5 years of soil exploitation, which leads to a fall in productivity and increased working time. The purpose of the project is to conceive innovating systems which allow a faster restoring of fertility so that clear cut land agriculture may take part in the satisfaction of the food needs of the populations. Research works on agro-forestry systems conducted in Brazil and at INRA AG, associating leguminous plants and timber trees, could be enhanced in the Guyanese context.

2-3) Conceiving fodder plants management methods allowing to satisfy the food needs of the ruminant cattle all over the year: Guyana goes through a long dry season in the course of which a significant weight drop of the original livestock can be observed, with a major effect on the subsequent animal performances. The reproduction rhythm is thus highly affected. A CIRAD team has recently worked on the Guyanese grassland potential in order to better pilot the grazing. These works have so far found low actualization. This project is supposed to widen and spread these works, and experiment new local fodder plant cultures.

Conclusion

The co-creation of work schedules will go on during the following months and everyone's function will be defined in accordance with the partnership agreements. An assossiaton will also be created to recruit a project leader for each of the transfer projects. Finaly, these first steps in the setting-up of a partnership will not take shape without a strengthening of the teams inside the development structures.