Tarek Chanegrih

Applying a typology of management accounting change: A research note

Introduction

Since advocacy by [START_REF] Hopwood | On Trying to study accounting in the context in which it operates[END_REF] in Europe and [START_REF] Kaplan | Measuring Manufacturing Performance: A New Challenge for Management Accounting Research[END_REF] in the USA, the study of change in management accounting control systems (MACS) has become an increasingly popular research topic. Using a range of methods, researchers have examined the motivations, constraints and consequences of change in management accounting (MA) (e.g. [START_REF] Innes | The process of change in management accounting: some field study evidence[END_REF][START_REF] Scapens | Accounting and control: a case study of resistance to accounting change[END_REF][START_REF] Ezzamel | Organisational change and accounting: understanding the budgeting system in its organisational context[END_REF][START_REF] Malmi | Towards explaining activity-based costing failure: accounting and control in a decentralised organisation[END_REF][START_REF] Vaivio | Exploring a non-financial management change[END_REF][START_REF] Burns | Conceptualising Management Accounting Change: an Institutional Framework[END_REF][START_REF] Granlund | Towards explaining stability in and around management accounting systems[END_REF][START_REF] Lukka | Management accounting change and stability: loosely coupled rules and routines in action[END_REF]. Yet researchers largely neglected identification of the volume and location of MA change until [START_REF] Libby | Predicting Change in Management Accounting Systems[END_REF]. Moreover, the nature of change has frequently been taken for granted by researchers [START_REF] Quattrone | What Does Organisational Change Mean? Speculations on a Taken For Granted Category[END_REF]. [START_REF] Sulaiman | Utilising a typology of management accounting change: An empirical analysis[END_REF] were the first to develop a typology of change in MA (addition, replacement, output modification, operational modification and reduction) in order to study both its nature and location.

The results of their research in Malaysian companies show that various types of change are represented in all MA sub-systems, with the exception of MA reduction, which was not observed in any of the companies surveyed.

The purpose of this research is to replicate and extend S and M's study in French manufacturing companies. Similar results are evident in the location and nature of change although some differences are apparent, which can be explained by national cultures and macroeconomic factors.

Two extensions to S and M are also introduced. First, this study refines S and M's typology by separating output modification into two dimensions, information representation changes and information frequency changes. We find it relevant to separate changes in information frequency, which are required for rapid responses in the face of greater competition [START_REF] Gordon | A Contingency Framework for the Design of Accounting Information Systems[END_REF], from changes in the representation of information, which are introduced to improve internal communication (Moores and Yven, 2001). This extension enhances examination of the heterogeneous nature of change in MA. Second, this study sets out to examine the factors contributing to the success of the changes made. We especially want to assess top management support [START_REF] Innes | Activity Based Costing: A Survey of CIMA Members[END_REF][START_REF] Shields | An empirical analysis of firms' implementation experiences with activity-based costing[END_REF][START_REF] Innes | Activity Based Costing In The UK's Largest Companies[END_REF][START_REF] Krumwiede | The implementation of activity-based costing and the impact of contextual and organizational factors[END_REF][START_REF] Innes | Activity Based Costing in the UK's largest companies: a comparison of 1994 and[END_REF], the level of complexity/simplification [START_REF] Sulaiman | Utilising a typology of management accounting change: An empirical analysis[END_REF], and the degree of resistance to change [START_REF] Johnson | Relevance lost: the rise and the fall of management accounting[END_REF][START_REF] Argyris | Implementing new knowledge: the case of activity-based costing[END_REF][START_REF] Shields | An empirical analysis of firms' implementation experiences with activity-based costing[END_REF].

Empirical analysis

Data collection

The study was designed to compare our findings with those of [START_REF] Libby | Predicting Change in Management Accounting Systems[END_REF] in Canada, [START_REF] Williams | Predicting Change in Management Accounting Systems: National Culture and Industry Effects[END_REF] in Singapore and Sulaiman and Michell (2005) in Malaysia.

After advance testing with controllers and financial officers, our questionnaire was sent in March 2006 to a sample of 320 manufacturing companies with more than 100 employees, to conform to the L and W (1996) and W and S (2001) 1 sample selection criteria. After two follow-up letters and calls, 74 replies were obtained. One firm was eliminated as it has fewer than 100 employees. Two respondents with less than four (4) years of service in their positions were also discarded, as were six (6) incomplete questionnaires. This yielded a final aggregate sample of 65 firms, or a 20% response rate for the study. A profile of the final sample is given in table 1. 66% of respondents are controllers, 30% are chief financial officers and 4% are plant managers. 78% of companies that responded to the questionnaire belong to a group. The existence of possible response bias between the early and late responses was checked by a t-test: no significant differences were found in the 1 No size constraint was indicated in the study conducted in Malaysia.

results. Furthermore, the t-test reveals no significant differences in terms of size between respondents and non-respondents.

Results regarding change location

Table 2 reveals that the average annual number of changes in French companies (1.40) was higher than in Singaporean companies (1.23) but lower than in Canadian companies (1.48) and Malaysian companies (1.90). Although the average annual number of changes and their distribution between location vary, change locations are broadly similar: controlling, decision-making and planning comprise the top 3 in all four studies. Costing and directing therefore appear to be the slowestchanging sub-systems despite the prominence of costing innovations such as ABC, life cycle costing and quality costing. This confirms that new costing models spread slowly in France [START_REF] Mévellec | Les paramètres de conception des systèmes de coûts, étude comparative[END_REF].

Results regarding the nature of change

The significant responses accorded to both information frequency and information representation changes (table 3) provide justification for the refinement made to S and M's typology (2005). Apart from the general similarities in the nature and location of MA change, three major differences are noteworthy. First, addition and replacement are contrastingly distributed. French companies seem to favour extending MACS by introducing new techniques, whereas Malaysian companies prefer to replace techniques. Second, despite the very low scores for reduction, this type of change is observed in France, but in none of the Malaysian companies. Third, the number of French companies that made no changes is high compared to Malaysian companies.

Results regarding change management

Table 4 shows the relatively low degree of resistance to change compared to the top management support and level of complexity. It also indicates that top management support and level of complexity score highest for the introduction of new techniques (addition and replacement).

Operational modifications are the least important type of change and show the lowest degree of top management support. The introduction of new techniques, such as replacement or extension, is the most important and successful form of change within the responding companies.

Discussion

Discussion on location results

The consistently low ranking of costing systems in all the studies is suggestive of a widespread lack of practical interest in high profile developments such as ABC [START_REF] Innes | Activity Based Costing In The UK's Largest Companies[END_REF][START_REF] Lukka | Cost Accounting in Finland: Current Practice and Trends of Development[END_REF][START_REF] Israelsen | Management Accounting in Denmark: Theory and Practice[END_REF][START_REF] Ask | Cost Management in Sweden: from Modern to Post-Modern[END_REF]Sherrer, 1996;[START_REF] Gosselin | The Effect of Strategy and Organisational Structure on the Adoption and Implementation of Activity Based Costing[END_REF][START_REF] Chenhall | Adoption and Benefits of Management Accounting Practices: An Australian study[END_REF][START_REF] Malmi | Activity-based costing diffusion across organizations: an exploratory empirical analysis of Finnish firms[END_REF][START_REF] Innes | Activity Based Costing in the UK's largest companies: a comparison of 1994 and[END_REF][START_REF] Mévellec | Les paramètres de conception des systèmes de coûts, étude comparative[END_REF].

Differences in the overall annual rates of change are apparent. They may be caused by macroeconomic circumstances. Companies operating in a difficult economic context are under pressure to improve efficiency. This creates internal demand for MA information with a resulting tendency to change MA techniques more frequently [START_REF] Williams | Predicting Change in Management Accounting Systems: National Culture and Industry Effects[END_REF]. The annual number of changes is therefore much higher in Malaysia than in any other country. The Asian exchange rate crisis offers a justification for this pattern of results [START_REF] Sulaiman | Utilising a typology of management accounting change: An empirical analysis[END_REF].

Ontario, where the Canadian study took place, suffered an economic recession between 1991 and 1993 and this may account for its second ranking in volume of change. France, with lethargic economic growth during the study period, ranks third. The relatively low number of changes in Singapore could be explained by the fact that Singaporean companies, in a high economic growth environment, had little incentive to prioritize changes in MA.

It is also apparent that the rank of the average number of changes in each type of location varies.

For example, controlling systems rank first in France, second in Malaysia and Canada but only third in Singapore. Controlling system changes included changes in the way performance was measured at the individual and organizational levels, as well as changes in performance evaluation in terms of quality and customer service. It is possible that France ranks first in controlling systems because of cultural dimensions [START_REF] Hofstede | Culture's consequences: international differences in work-related values[END_REF][START_REF] Hofstede | Cultures and organizations: software of the mind[END_REF]. In terms of cultural profile, France has the highest score in uncertainty avoidance (table 6). Low tolerance for ambiguity could prompt companies to reduce uncertainty avoidance through controlling. This hypothesis is reinforced by the fact that Singaporean companies, with their high tolerance for ambiguity, have the lowest rank for controlling (in the top three types of location), and that Malaysian and Canadian companies, which have medium tolerance for ambiguity, occupy medium rankings in controlling. In addition, it can be argued that decision-making systems rank second in this study because the need for rapid responses grows as competition intensifies, and most of the respondents (78% of questionnaire respondents) were subsidiaries of larger groups in which internal reporting is required. Planning systems rank third in France. Canadian (table 6) and French companies tend to a short-term view and this could explain why the companies in these two countries do not appear to prioritize changes in this area. In contrast, Malaysian and Singaporean companies, closer to Chinese culture and thus taking a longer-term view, respectively rank first and second in planning systems. Source: [START_REF] Hofstede | Culture's consequences: international differences in work-related values[END_REF][START_REF] Hofstede | Cultures and organizations: software of the mind[END_REF].

Discussion on the nature of change

The results of this study regarding information representation change and information frequency change validate the refinement made to S and M's typology by enhancing examination of the heterogeneous nature of change.

Three differences should be noted. First, reduction was not observed in any Malaysian company, whereas four French companies removed a MA technique. This difference could be explained by the degree of individualism/collectivism in the country's culture. Collectivist cultures, which tend to think in terms of "we" instead of "I", emphasize harmony [START_REF] Hofstede | Culture's consequences: international differences in work-related values[END_REF] and eliminating techniques introduced by other people can create tensions within the company. Power distance [START_REF] Hofstede | Culture's consequences: international differences in work-related values[END_REF], which is especially high in Malaysia, could reinforce this result if the persons who introduced the techniques has a high-responsibility job. Indeed, the proportion of French companies which made no change is much higher than that of Malaysian companies. This may result from the macroeconomic context. More intensely competitive environments may have led Malaysian companies to change MA techniques [START_REF] Libby | Predicting Change in Management Accounting Systems[END_REF]. Finally, French companies introduced three times more replacement, whereas Malaysian companies introduced three times more addition. The degree of individualism/collectivism [START_REF] Hofstede | Culture's consequences: international differences in work-related values[END_REF] could explain why French companies are more inclined to add innovative solutions to existing systems. Managers in collectivist cultures pay little attention to new or fashionable management ideas, whereas managers in individualistic cultures keep up to date with new ideas and try to put them into practice [START_REF] Hofstede | Culture's consequences: international differences in work-related values[END_REF]. In individualistic cultures, strength comes from initiative and personal achievements.

Although French companies seem to carry out more radical changes than Malaysian companies, incremental changes (replacement, output modification and operational modification) clearly predominate in both countries. The general MA framework is preserved over time, and changes seem to be more an evolution than a revolution [START_REF] Bromwich | Management accounting: evolution not revolution[END_REF]). These results corroborate recent studies which see MA change as a relatively slow process of change in organizational routines and rules [START_REF] Scapens | Never Mind the Gap: Towards an Institutional Perspective On Management Accounting Practice[END_REF][START_REF] Burns | Conceptualising Management Accounting Change: an Institutional Framework[END_REF].

Discussion on change management

The degree of resistance to change was low. Strong support from top management is one factor likely to contribute to the level of resistance. Operational modifications score lowest in top management support, probably because of the purely technical nature of this type of change. The introduction of new techniques is the most important and successful type of change. The correlation matrix indicates that management heavily influences the most important and apparently most complex changes and this support lowers the degree of resistance to change.

Overall

This study confirms that MA is a practice which exhibits extensive and consistent change. It also shows that while many aspects of the volume and pattern of that change show consistency across countries and continents there are notable differences which can be attributed to economic circumstances and cultural differences.

Table 1

 1 Profile of sample firms

	Number of	Number of firms	% (France)	% (Singapore)	% (Canada)
	employees	(France)
	0-149	10	15.38	27.95	33.33
	150-299	24	36.92	27.95	29.16
	300-499	11	16.92	11.82	16.66
	450-999	10	15.38	16.12	4.16
	> 1000	10	15.38	16.12	16.66
	Total	65	100	100	100

Table 2

 2 The location of change in different countries (

This study, France, 2002-2005) (Sulaiman and Mitchell, Malaysia, 1997-2001) (Libby and Waterhouse, Canada, 1991-1993) (Williams and Seaman, Singapore, 1995-1997) N= 65; response rate = 20% N=92; response rate = 29% N=24; response rate = 34% N=93; response rate = 45%

		Number of changes	Average number of annual changes	External ranking	%	Internal ranking	Number of changes	Average number of annual change	External ranking	%	Number of changes	Internal ranking	Number of changes	Average number of annual changes	External ranking	%	Internal ranking	Number of changes	Average changes number of annual	External ranking	%	Internal ranking
	Controlling	103	0.40	3	28.38	1	221	0.48	1	25.3	32	2	32	0.44	2	29.9	2	80	0.28	4	23.25	3
	Decision-making	82	0.32	4	22.58	2	191	0.42	2	21.8	34	3	34	0.47	1	31.8	1	93	0.33	3	27.03	1
	Planning	68	0.26	3	18.74	3	241	0.52	1	27.5	17	1	17	0.24	4	15.9	3	87	0.31	2	25.29	2
	Costing	63	0.24	2	17.35	4	162	0.35	1	18.5	13	4	13	0.18	3	12.1	4	34	0.12	4	9.83	5
	Directing	47	0.18	2	12.95	5	60	0.13	4	6.9	11	5	11	0.15	3	10.3	5	50	0.19	1	14.53	4
	Total	363	1.40	3	100		875	1.90	1	100	107		107	1.48	2	100		344	1.23	4	100
	N : number of respondents

Table 3

 3 The nature of change in France and Malaysia

	(This study, France)

Table 4

 4 Average change management scores

		Importance Success Top management	Level of	Resistance to change
				support	complexity
	Addition	1.45 2	1.75	1.81	1.03	0.44
	Replacement	1.64	1.58	1.58	1.35	0.50
	Information frequency	1.24	1.35
	change			1.48	0.72	0.51
	Information	1.10	1.00
	representation change			1.51	0.79	0.46
	Operational	1.04	1.08
	modification			1.38	0.92	0.56
	Reduction 3	-	-	-	-	-
	Pearson's matrix (table 5) indicates that importance and success are correlated. A smaller degree of
	correlation is observed between the level of complexity and importance, top management support
	and success, and top management support and the degree of resistance to change.

Table 5

 5

	Pearson's correlation matrix
		Success	Top management	Level of complexity	Resistance to change
			support
	Importance	0.873**	0.656	0.817*	-0.372
	Success		0.829*	0.594	-0.43809
	Top management			0.377	-0.825*
	support
	Level of complexity				-0.046
	** p<0.05 * p<0.1

Table 6

 6 Cultural cues in the four countries

		Power distance Uncertainty	Individualism/collectivism	Masculinity/	Confucian
			avoidance		femininity	dynamism
	France	68	86	71	43	-
	Malaysia	104	36	26	50	-
	Singapore	74	8	20	48	48
	Canada	39	48	80	52	23
	Mean	57	65	43	49

Average ratings based on a three-point Likert scale (0=low, 1=medium, 2=high).

Due to its extremely low scores, reduction is left out of the following analyses.

Acknowledgments

I would like to thank Professor Robert Scapens and two anonymous reviewers for their constructive comments.


Alexandra T Tapsoba
email: atapsoba@issp.bf

Researcher

Professor, Pascale Combes Motel

Professor, Jean-Louis Combes
email: j-louis.combes@uca.fr

Catherine Araujo-Bonjean

Keywords: Food security, Climate variability, Remittances, Burkina Faso. JEL Codes D13, F24, Q54, N57

This paper assesses the impact of remittances and climate variability on the food security of households in Burkina Faso. It draws from the World Bank 2010 survey on migration and remittances in Burkina Faso and uses a database from Burkina Faso's Department of Meteorology regarding rainfall recorded in the ten weather stations throughout the country between 2001 and 2010. We build a food security index using principal component analysis that encompasses the accessibility and utilization dimensions of the concept. We also compute an inter-annual rainfall index and the latter is found to have a negative impact on food security. After controlling for potential endogeneity issues using distance variables and migrant characteristics as instruments, remittances are found to enhance food security. Results are robust to alternative measures of food security and alternative calculations of rainfall variability. The paper also highlights that remittances dampen the negative effect of rainfall variability on food security.

Introduction

Drastic changes in rainfall and temperature have dramatically affected agricultural production in Sub-Saharan Africa (SSA) [START_REF] Barrios | The Impact of Climatic Change on Agricultural Production: Is It Different for Africa?[END_REF]. Climate variability has also adversely impacted farmers' incomes, especially for dryland crops and livestock [START_REF] Kurukulasuriya | Will African Agriculture Survive Climate Change?[END_REF]. In 2014, the Intergovernmental Panel on Climate Change (IPCC)'s fifth assessment report on adaptation highlighted key risks related to increased stress on water resources, as well as reduced crop productivity, which may have strong adverse effects on the welfare of rural and urban households for developing countries. In this context, climate variability is expected to further shape future food security in African countries (Intergovernmental Panel on Climate Change, 2014). Climatic failures will arguably produce the most significant consumption shocks [START_REF] Porter | Shocks, Consumption and Income Diversification in Rural Ethiopia[END_REF] Indeed, environmental disasters have been shown to be one of the major underlying drivers of food insecurity, as well as of poverty and conflict in African countries (Misselhorn, 2005).

Food security therefore remains at the top of development policy agendas in SSA, where the proportion of undernourished people reached a 26.8% average between 2010 and 2012 [START_REF] Porter | Food Security and Food Production Systems[END_REF] and where the share of income spent on food is particularly high, especially for poor households [START_REF] Chauvin | Food production and Consumption Trends in Sub-Saharan Africa: Propsepcts for the Transformation of the Agricultural Sector[END_REF]. Changes in rainfall and temperature patterns are expected to affect all dimensions of food security, which are food availability, food access, food use and price stability [START_REF] Schmidhuber | Global food security under climate change[END_REF]. Crop losses due to climate variability critically affect food availability, especially when households depend on rain-fed agriculture. The destabilizing effect of extreme climate events, which are expected to become more frequent, exacerbate the vulnerability of all food-insecure people. In terms of food utilization, people may not be able to get the necessary diversity of food nutrients as they will be rationing their consumption to prioritize calorie-rich but nutrient-poor foods [START_REF] Bloem | An introduction to the impact of climate change, the economic crisis and the increases in the food prices on malnutrition[END_REF]. Finally, climate variability may also contribute to increases in food commodity prices [START_REF] Niang | Africa in climate change 2014: impacts, adaptation, and vulnerability[END_REF].

Adaptation strategies, therefore, play a crucial role in preventing further detrimental effects of climate change on food security in Africa. Adaptation targets help lowering risks and vulnerability and contribute to the search for diversification opportunities. For African populations who mostly depend on subsistence or rainfed agriculture, crop diversification is a widespread adaptation practice [START_REF] Harrower | Consumption smoothing in the zone Lacustre, Mali[END_REF]. In a context characterized by rising temperatures, declines in rainfall and more frequent extreme climate events, a significant number of African farmers have already changed their agricultural practices while diversifying crop varieties, changing dates of planting, increasing water conservation and using shading and sheltering techniques [START_REF] Maddison | The Perception of and Adaptation to Climate Change in Africa". The World Bank, Development Research Group -Sustainable Rural and Urban Development Team[END_REF]. Differences in the ability of individual farmers to adapt may, however, be significant due to the existence of material constraints. Indeed, farmers willing to adapt their farming practices may face numerous impediments related to their poverty and liquidity constraints. Relaxing the latter may, therefore, be critical for successful adaptation to climate change [START_REF] Di Falco | Does Adaptation to Climate Change Provide Food Security? A Micro-Perspective from Ethiopia[END_REF].

In this paper, we argue that remittances support farmers' adaptation strategies, which in the end strengthen food security in developing countries, especially in SSA. Migration, both cross-border and internal is the primary income diversification strategy practiced in developing countries and especially in SSA. Remittances have increased at an impressive rate since the beginning of the 2000s and now represent a major source of foreign inflows in developing countries [START_REF] Yang | Are remittances insurance? Evidence from rainfall shocks in the Philippines[END_REF]. A large body of the literature has already provided empirical evidence of the dampening effect of remittances on consumption instability [START_REF] Combes | Remittances and household consumption instability in developing countries[END_REF], income inequalities [START_REF] Chauvet | Impact des financements internationaux sur les inégalités des pays en développement[END_REF] [START_REF] Koechlin | International remittances and income inequality: an empirical investigation[END_REF], and poverty [START_REF] Adams | Do international migration and remittances reduce poverty in developing countries?[END_REF] [START_REF] Acosta | What is the impact of international remittances and poverty and inequality in Latin America?[END_REF], (Gupta, Pattillo & Wagh,2009). Though SSA countries do not rank among the top remittance-receiving countries, worker's remittances more than doubled between 2000 and 2006 (Mohapatra, Joseph, & Ratha, 2012). Personal remittances grew at an impressive 20% per annum over the 2001 to 2010 period, which is the highest average annual growth rate among developing regions (World Bank Indicators). Remittances arguably play a key role in dampening the effects of a large variety of risks, both, ex-ante or ex-post. For instance, the dampening effect of remittances on adverse shocks in SSA has been documented in several studies [START_REF] Combes | Are Remittances and Foreign Aid a Hedge Against Food Price Shocks in Developing Countries?[END_REF], [START_REF] Azam | Migrants' Remittances and the household in Africa: A Review of Evidence[END_REF]. Remittances have also buttressed ex-ante household preparedness for natural disasters and provided resources in their aftermath (Mohapatra, Joseph, & Ratha, 2012). This paper investigates whether remittances help improve food security threatened by climate risk, using Burkina Faso as a case study. To the best of our knowledge, little research has been done on the impact of remittances in Western African countries and Burkina Faso in particular. Some exceptions include a study that found that off-farm income, including remittances, improved food security in the Kwara state of Nigeria [START_REF] Babatunde | Impact of off-farm income on food security and nutrition in Nigeria[END_REF]. Remittances were also found to have a positive impact on the probability of rural Malian households to improve their food security levels [START_REF] Generoso | How do rainfall variability, food security and remittances interact? The case of rural Mali[END_REF]. Existing studies on Burkina Faso that focus on consumption and income smoothing were mostly made in the aftermath of the 1980s droughts. For instance, [START_REF] Christopher | Consumption Smoothing? Livestock, Insurance and Drought in Rural Burkina Faso[END_REF] questioned the consumption smoothing properties of livestock [START_REF] Reardon | Coping with Household-Level Food Insecurity in Drought-Affected Areas of Burkina Faso[END_REF]. [START_REF] Barbier | Human Vulnerability to Climate Variability in the Sahel: Farmers'Adaptation Strategies in Northern Burkina Faso[END_REF] highlighted that rural households from the Sudanian and Sahelian zones were strongly involved in income diversifying strategies in order to ensure food security. Interestingly, [START_REF] Christopher | Consumption Smoothing? Livestock, Insurance and Drought in Rural Burkina Faso[END_REF] pointed out that in Burkina Faso transfers are rooted in a complex gift exchange system. Insurance motives were not always the main motive for transfers. There is, therefore, room for new investigations on the role of remittances on household welfare measured under pervasive climate variability. This paper empirically innovates in several aspects. First, a food security index is built in order to encompass its multidimensional character. Second, an original dataset of meteorological recordings gathered at a fine level allows us to construct an index of climate variability. Third, the potential endogeneity of remittances is also addressed.

The rest of the paper is organized as follows. Section 2 sketches out the context of the study. Section 3 focuses on the construction and description of the food security index.

Section 4 presents our empirical framework, the main results, and robustness checks.

Remittance patterns in Burkina Faso

This study takes advantage of the 2010 Migration and Remittances household survey conducted under the auspices of the World Bank in Burkina Faso as part of the Africa Migration Project. This survey aimed to contribute to the improvement of migration and remittance impact on development in SSA. 1 The dataset used in this study is based on the answers collected on 2,102 rural and urban households in 7 regions, 10 districts and 77 villages surveyed in 2010 in Burkina Faso. It focuses on the southern parts of the country, which hosts the most intense migration provinces (Banwa, Boulgou, Boulkiemdé, Kadiogo, Namentenga, Passoré, Sanmatenga, Sourou, Tuy, Yatenga).

In Burkina Faso, most migration is internal and moves toward Ouagadougou and Bobo-Dioulasso, which are the country's largest cities. International migrants, however, made up at least 28.9% of the migrants in 2006 (Ministry of Economy and Finance, 2006).

According to the Central Bank of West African States, remittances represented 1.3% of the country's GDP in 2013, which is in line with the 2001-2010 personal remittances average calculated from the World Bank Indicators. One-third of this amount accrued to rural communities, which are the poorest and most vulnerable. Yet the majority of international remittances (30.9% of the total) come from Ivory Coast (Table 1). The 2009 survey on household living conditions undertaken by the National Institute of Demography of Burkina Faso showed that men, who mainly migrate for economic reasons, sent back the majority of remittances (87.4%).

Remittances are a critical source of income in Burkina Faso, especially for poor households. The majority of the money received is used to cover household consumption and investment expenses (Table 2). These expenses generally relate to education and housing. Remittances from workers located in Ivory Coast were correlated with the rise of poverty in Burkina Faso over the 1998-2003 period [START_REF] Lachaud | Crise ivoirienne, envois de fonds et pauvreté au Burkina Faso[END_REF]. This evidence is somehow in contradiction with previous results based on surveys conducted in the Central Plateau region, which concluded that the effect of remittances on poverty and income diversification was conditional on the destination countries of migrants 1 Other countries surveyed by the World Bank are Ethiopia, Kenya, Nigeria, Senegal, South Africa, and Uganda. [START_REF] Wouterse | Migration and Income Diversification: Evidence from Burkina Faso[END_REF] and [START_REF] Wouterse | Remittances, Poverty, Inequality and Welfare: Evidence from the Central Plateau of Burkina Faso[END_REF]. One may therefore further inquire about the role of remittances while looking at food security, which is a critical dimension of household welfare.

Food security

The literature includes several definitions of food security, as the concept itself has evolved through time and across socio-economic conditions since its first introduction in the early 1940s [START_REF] Hassan | Food Security and Child Malnutrition: The Impact on Health, Growth, and Well being[END_REF]. In the early 1970s, hunger and food shortages in SSA and

Asia led to a focus on Malthusian preoccupations, which relate food crises to the food supply. Later, the 1974 World Food Conference (Food and Agriculture Organization of the United Nations) defined food security as the "availability at all times of adequate world supplies of basic foodstuffs… to sustain a steady expansion of food consumption…. and offset fluctuations in production and prices". Accessibility issues arose in the 1980s with Sen's vision developed in Poverty and Famines [START_REF] Sen | Poverty and Famines. An essay on entitlement and deprivation[END_REF]. This work highlighted the fact that the capacity of people to have access to food is as important as food availability. In 2002, the (Food and Agriculture Organization of the United Nations) stated that food security occurs, "When all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food which meets their dietary needs and food preferences for an active and healthy life." It is now generally accepted in the literature that food security refers to four main dimensions: availability, accessibility, utilization, and stability.2

The World Bank household survey on Migration and Remittances covers several dimensions of food security. In the present case, two pillars are taken into account. They are food accessibility and utilization.3 A synthetic index is calculated using principal component analysis (PCA), which combines discrete and continuous variables. The World Food Program often applies PCA to generate food security indexes and draw household profiles. PCA is also used in case studies in Ethiopia (see e.g. (Demeke, Keil, & Zeller, 2011)).

In our case, accessibility and utilization of food could be referred to by the same variables. Detailed information is available about household expenditures for cereals, legumes, oleaginous, tubers, fruits, meat, chicken and eggs. As food expenditures also reflect the accessibility and dietary diversity of the eight major food groups4 and their uses5 , we capture both dimensions in these variables. Utilization also refers to the optimal use of food and is captured here by the presence in a given household of a room reserved for cooking and the presence of an internal faucet.

The results of the principal component analysis are reported in Table 3. They indicate that the first component explains 30.9% of the total variance within the data and that the second component explains only 25.7% of the variance. Table 3 also shows the variable loadings in the components. We kept the first component that is positively correlated with food expenditures: the possession of an internal faucet and the existence of a separate room for cooking. We then consider this first component to be our index of food security.

The value of the Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy is 0.53, showing relatively compact patterns of correlations between the variables and justifying the use of principal component analysis.

Climate variability

Burkina Faso is characterized by tropical and mainly Sudano -Sahelian weather. The country can be divided as presented in the introduction into three main regions: the Sahel region, which averages less than 600 mm of rainfall per year, the north Sudanian region, which averages between 600 mm 900 mm of annual rainfall, and a south Sudanian region, which averages more than 900mm of rainfall annually.

Temperatures have risen globally in the country over the past years, and according to the Department of Meteorology of Burkina Faso (Permanent Secretary of the National Council for Environment and Sustainable Development, 2007) a rise of 0.8° C is expected by 2025 and of 1.7°C by 2050 that will mainly contribute to evapotranspiration levels across the country. The Department of Meteorology actually states that the country records 206.9 billion cubic meters of rain every year. From this amount, 15.66% infiltrates the soil, and 80.18% evaporates. These figures highlight the importance of understanding climate variability's impact on food security in a country, which is highly dependent on subsistence and rain-fed agriculture. It is also important to note that the years 2009 and 2010 were critical years for the country, as it experienced some highly destructive floods.

An inter-annual rainfall variability index, based on the definition of [START_REF] Barros | Long term changes in African rainfall[END_REF] is constructed. Data used are precipitations (mm) measured by 10 stations 6 across the country and provided by the National Institute of Meteorology of Burkina Faso. The index is basically the absolute value of a reduced central variable calculated on annual precipitation [START_REF] Servat | Climatic variability in humid Africa along the Gulf of Guinea Part1: detailed analysis of the phenomenon in Côte d'Ivoire[END_REF].

Following (Mohapatra, & Ratha, 2012), we also compute this index using further historical data that are available on rainfall records since 2001. 7 The computed index is then assigned to households according to the geographical proximity of their village to the weather station in the database8 . We compute further down the line another index referring only to the number of months of the year with rainfall, which corresponds to the cropping season. This season generally goes from June to September and climate conditions during this time determine household harvests for the coming year.

The index is calculated as

𝑍 𝑖 -𝑍 ̅ 𝜎
where 𝑍 𝑖 represents the 2010 precipitation highs for each station indexed by 𝑖. 𝑍 ̅ is the annual rainfall average between 2007 and 2010, and 𝜎 is the standard deviation of annual precipitations over this period. It is worth noting that the rainfall variability index can also be interpreted as an indicator of perceived variability. Field surveys conducted in the Central Plateau of Burkina Faso provided evidence that perceptions on the amount or frequency of rainfall were closely correlated with rainfall records [START_REF] West | Local Perceptions and Regional Climate Trends on the Central Plateau of Burkina Faso[END_REF].

Econometric analysis

Empirical framework

The basic econometric specification used to capture the impact of remittances on food security is the following:

𝑌 𝑖 = 𝛼 0 + 𝛼 1 𝑅 𝑖 + 𝛼 2 𝑅𝑎𝑖𝑛𝑉𝑎𝑟 𝑖 + 𝐗′ 𝐢 𝛃 + 𝜀 𝑖 (1)
Where 𝑌 represents the food security index, 𝑅 is the amount of remittances received by the household in FCFA divided by 1000, 𝑅𝑎𝑖𝑛𝑉𝑎𝑟 is the index of rainfall variability and 𝐗 is a vector of other explanatory variables including province dummies, a list of which is available in Appendix 1.

αs and 𝛽s are coefficients to be estimated. It is expected 𝛼 1 > 0 and 𝛼 2 < 0. 𝜀 is the error term. 𝑖 is a household index, with 𝑖 = 1, … , 2,102, which is the maximum number of households. Other explanatory variables pertain to household human capital such as the number of people who can read and write in French and the head of household characteristics such as gender and age. Having a male head of household can have a positive impact on food security, given the fact that in some developing countries, men are often the household breadwinners. The potential labor force available in the household, measured by the number of male teenagers is also included and is expected to have a positive impact on food security. Lastly, a dummy variable taking the value of 1 if the household is in a rural area, and 0 otherwise, as well as the number of children in the households are also included and expected to have a negative impact on food security.

This result is expected given that rural areas are commonly poorer and can be expected to be less food-secure than urban areas. Many children in the household can lower expenditures on food to the benefit of expenditures on health, education and so on and therefore lower food security levels.

Descriptive statistics of these control variables are reported in Table 4 below. The basic specification can be augmented in the following manner:

𝑌 𝑖 = 𝛼 0 + 𝛼 1 𝑅 𝑖 + 𝛼 2 𝑅𝑎𝑖𝑛𝑉𝑎𝑟 𝑖 + 𝛼 3 𝑅 𝑖 × 𝑅𝑎𝑖𝑛𝑉𝑎𝑟 𝑖 + 𝐗′ 𝐢 𝛃 + 𝜀 𝑖 (2)
It is still expected that 𝛼 2 < 0 while 𝛼 3 > 0 so that remittances improve household food security in a context of climate variability. This specification allows determining the value of remittances, which significantly dampens the negative effects of rainfall variability on food security. It is calculated as follows:

𝜕𝑌 𝜕𝑅𝑎𝑖𝑛𝑉𝑎𝑟 = 𝛼 2 + 𝛼 3 𝑅 𝑖 . Solving for 𝜕𝑌 𝜕𝑅𝑎𝑖𝑛𝑉𝑎𝑟 = 0 allows us to calculate the amount of remittances that cancels out the effect of climate variability on food security.

We begin by providing OLS estimates, which will be completed by a series of robustness checks, and lastly the use of instrumental variables.

Results

OLS results of the baseline specification (equation 1) are presented in Table 5. Control variables are gradually included so as to check the sensitivity of the effect of remittances to additional control variables. Results show that remittances have a positive impact on household food security. Climate variability, on the other hand, significantly and negatively affects food security. As expected, living in a rural area has a negative impact, somehow validating our hypothesis that rural households are poorer. Having a man as head of household as well as having a certain amount of male teenagers, significantly and positively impacts food security. Other variables such as children and the head of the household's age do not seem to have any robust impact on food security. Equation 2 introduces the interactive term of the remittances crossed with the rainfall variability index. The results of this estimation are presented in Table 6. It should be noted that the coefficient associated with the interaction between remittances and the rainfall index is positive and significant, while the rainfall index introduced additively has a negative impact on food security, as expected. Remittances then significantly dampen the negative effects of rainfall variability on food security.

Robustness checks

The robustness of the results is assessed in different ways. First, we check whether the results are affected by the definition of the rainfall variability index. We consider (i) a broader temporal range of coverage with rainfall variability computed starting in 2001 instead of 2007, and (ii) a rainfall variability index accounting for the cropping season, due to the population's practice of subsistence agriculture. Second, we consider that the food security index is measured as per capita food expenditures. Third, we try to check whether the results are affected by the magnitude of remittances received by households and consider the 50% of households that receive the highest amounts in remittances.

Table 7 shows that previous findings are accurate, even when the year of the rainfall index calculation is changed. In addition, food expenditures react similarly to remittances.

When we look at the 50% of households that receive the highest amounts in remittances, we find that this source of income still has a positive impact on food security.

Instrumentation

The main concern for identification concerning remittances is their potential endogeneity. The first source of potential endogeneity can come from the non-inclusion of some omitted variables that can bias the relationship between remittances and food security. Also, there is a high probability that remittances and food security influence each other [START_REF] Gupta | Effect of remittances on poverty and financial development in Sub-Saharan Africa[END_REF]. On the one hand, migration (leading to remittances) can constitute an adaptive strategy for households that experience food insecurity. On the other hand, remittances can influence food security, as they constitute an important source of income for poorer and less food-secure households. In order to tackle the potential endogeneity of remittances, we proceed to instrumentation using two variables.

Table 8 shows the results of instrumenting with one variable (IV1) and with two variables (IV2), as well as the statistics of Wald and Sargan, accordingly. Column (IV1) therefore presents the results when the model is perfectly identified, and column (IV2) when the model is overidentified.

The first instrument accounts for the migrant level of education and is a variable that takes the value of 1 if the migrant has at least a primary level of school, and 0 otherwise. 9 . The relationship between a given migrant's education and remittances is ambiguous. Early literature tends to conclude that migration of the skilled, or the brain drain has a negative impact on potential remittances in the home country [START_REF] Bhagwati | The international brain drain and taxation: a survey of the issues[END_REF]. However, today the literature is less clear-cut. On the one hand, more skilled migrants can remit less as they often come from richer families and are more likely to migrate with their entire household [START_REF] Faini | Remittances and the brain drain: do more skilled migrants remit more?[END_REF]. In this case, sending remittances back to the origin country does not really make sense. On the other hand, migrants can remit more as they are more educated and less likely to be illegal [START_REF] Docquier | Remittances, Migrant's Education and Immigration Policy: Theory and Evidence from Bilateral Data[END_REF]. Hence, they can have access to banks and cheaper transfers, and can consequently remit more. [START_REF] Docquier | Remittances, Migrant's Education and Immigration Policy: Theory and Evidence from Bilateral Data[END_REF]) also theoretically and empirically investigate the relationship between remittances and migrant education using several databases on migration, accounting for a large panel of origin countries.

Their model suggests that a migrant's education has a positive impact on remittances 9 As households can have more than one migrant, we took the mean level of schooling for all migrants in the household.

when the immigration policy of the destination country is more restrictive and less skillselective. In a cross-country macroeconomic work (Niimi & al 2010) find that remittances decrease with the share of migrants with tertiary education. The authors argue that this might be a reason why source countries may prefer unskilled migration. In a theoretical and empirical work on developing countries [START_REF] Faini | Remittances and the brain drain: do more skilled migrants remit more?[END_REF] shows that skilled migrants have a lower propensity to remit from a given flow of earnings.

Table 8 allows us to understand that for this specific case study, migrants with at least a primary school level remit more.

Our second instrument is inspired by (Christopher & Zenteno, 2007) and [START_REF] Asli | Remittances and Banking Servives: Evidence from Mexico[END_REF], who use distance from migrants' households to railway lines to explain migration and remittance patterns in Mexico. We believe that using this instrument allows us to capture a historical pattern of migration, in order to explain more recent and current patterns and therefore use the distance between the households and the sole railway, leading to Ivory Coast, to capture the flow of migration and remittances. Using distance to railway can be a good way to do so in Burkina Faso, as the history of this railway infrastructure is linked to the population's migration and movement across the country.

This railway, which spans 1,260 km today, was constructed between 1904 and 1954 and connects Abidjan in Ivory Coast to Ouagadougou in Burkina Faso. The construction reached Ferkessedougou, a city at the border between the two countries in 1926 and the first city of Burkina Faso, Bobo Dioulasso in 1934. Burkinabe men who were seen as a source of labor force in sub-Saharan Africa during colonial times, were the main builders of the railway [START_REF] Coulibaly | Using panel data to estimate the effect of rainfall shocks on smallholders food security and vulnerability in rural Ethiopia[END_REF].

The work of [START_REF] Piché | Entre le mil et le franc: un siècle de migrations circulaires en Afrique de l'Ouest, le cas du Burkina Faso[END_REF] on migration patterns in West Africa shows that nearly 61,000 Burkinabe migrants, half of them originating from the central part of the country, worked on the railway which was called "the railway of the Mossi" after the main ethnic group of Burkina Faso originating from the central regions. Piché and Cordell also describe how internal and international migration was facilitated by the extension of the railway to Ouagadougou in 1954.

It is well recognized that in developing countries internal migration moves from rural areas toward the largest and major cities, as migrants hope to find better economic opportunities in cities. According to [START_REF] Coulibaly | Using panel data to estimate the effect of rainfall shocks on smallholders food security and vulnerability in rural Ethiopia[END_REF], the most dynamic cities in 1975 in terms of migration were Koudougou for its textile industry, and Banfora, mainly because of the trade generated by the railway via Ivory Coast.

Regarding international migration, it is necessary to understand the complex history between Burkina Faso and Ivory Coast, of them [START_REF] Piché | Entre le mil et le franc: un siècle de migrations circulaires en Afrique de l'Ouest, le cas du Burkina Faso[END_REF]. After the independence of both countries in the 1960s, this pattern remained thanks, for instance, to the expansion of the railway line between Burkina Faso and Ivory Coast.

We argue that the proximity of the railway line can have an impact on the development Luminosity data use for social and environmental research responds to the difficulty in some developing countries to find reliable subnational socioeconomic data. Night-time luminosity data can be considered as a good proxy of economic and demographic variables. It has been shown to be highly correlated with income [START_REF] Chen | Using luminosity data as a proxy for economic Statistics[END_REF]. In the same vein, frequency of lighting can predict GDP per capita at national and 10 Historical main destination of Burkina Faso international migrants.

11 Upper Volta at the time.

12 This variable is taken from the yearly reports of the « Institut National de la Statistique et de la Démographie » of Burkina Faso and represents the proportion of people living under the poverty line per region.

subnational levels [START_REF] Ebener | From wealth to health: modelling the distribution of income per capita at the sub-national level using night-time light imagery[END_REF]. This luminosity variable is computed using stable light data presented in digital numbers from 0 to 63. These digital numbers are then summed up to calculate aggregate luminosity for a 1° longitude  1° latitude grid cell.

Results in Table 8 show that when instrumenting, remittances still positively impact food security and have a higher coefficient, while rainfall variability has a negative effect.

The proportion of people living under the poverty line has a negative impact on food security, as expected. Hence, based on this particular survey, households may need nearly half of the GDP per capita of the year to cope with the negative impact of rainfall variability on food security.

For robustness purposes, we extend results of Table 9 by introducing additional control variables. Our results are still robust, and go along with our main findings.

Conclusion

In this paper, we investigated ed the effect of remittances on food security for the year 2010 while matching data from the World Bank survey on migration and remittances in Burkina Faso and rainfall data recorded by the ten weather stations across Burkina Faso.

We demonstrate that remittances had a positive and significant impact on household food security, while rainfall variability affected food security negatively. These results are robust to the inclusion of several control variables as well as alternative measures of climate variability, subsampling of the data, and instrumentation. We also show the role of remittances in dampening the negative effect of rainfall variability on food security and calculate the amount necessary to cancel the negative effect of climate variability.

Our results indicate that migration can be considered as a viable strategy for coping with food insecurity. It is therefore important to encourage any policy that aims to improve the ease of sending this important source of income back to migrants' origin countries. In addition, Burkina Faso is likely to experience more episodes of climate disorder in the near future. Helping populations to invest remittances in activities other than agriculture can be a risk management, strategy and a way of reducing dependence on rain-fed agriculture, which is highly sensitive to climate conditions. Though remittances have been shown helpful in enhancing food security, they should be complementary devices in a broader set of national and international assistance initiatives. As the IPCC's fifth assessment on adaptation points out, "Across the continent, most of the adaptation to climate variability and change is reactive in response to shortterm motivations, is occurring autonomously at the household level, and lacks support from government stakeholders and policies". Given the intensification of climate variability and natural disasters, it may well be necessary to focus on ex-ante adaptation strategies, targeting the most vulnerable populations, who are usually also the poorest.

Such strategies should, therefore, be financed by government initiatives with the aid of migrant input, through remittances. Policies and initiatives that can foster the facility of remittances should, therefore, be encouraged.

  of regions and the development of markets, inevitably impacting food security. To control for the potential impact of the development of the region, we firstly include a variable accounting for the incidence of poverty in the region12 , to take into account the development of the different regions. Secondly, we use the night-time luminosity intensity recorded between 2009 and 2010 at the household's geographical location to take into account the different levels of development within villages and more precisely among households.

Table 1 . International remittances, by origin countries in 2009 Origin Amount (in FCFA) % of total remittances

 1

	Côte d'Ivoire	17 108 661 241	30.9
	West African Economic and	4 595 530 366	8.3
	Monetary Union Countries
	Ghana	609 046 193	1.1
	ECOWAS countries	332 207 014	0.6
	France	5 204 576 559	9.4
	Italy	6 367 301 109	11.5
	USA	8 360 543 195	15.1
	Rest of the world	12 789 970 054	23.1
	Total	55 367 835 730	100.0
	Source: (Central Bank of West African States, 2011)

Table 2 . Remittance spending by households Amount (F CFA) % of total remittances

 2

	Consumption	9 210 882 416	37,3
	Health	543 269 204	2,2
	Education	3 704 108 210	15,0
	Property investment	6 346 372 067	25,7
	Other investment	4 025 130 922	16,3
	Savings	370 410 821	1,5
	Family events	419 798 931	1,7
	Other	74 082 164	0,3

Total 24 694 054 736 100,0 Source: Central Bank of West African States (2011) 3 Stylized facts on food security and climate variability

  and temperature parameters, which are then compiled by the General Meteorological Department of Burkina Faso (Direction Générale de la Météorologie). This rich data set is available from 2000 onwards and serves as a basis for various climate variability indices, which are presented in Section 3.2.

	The database gathered by the World Bank's Migration and Remittances household
	survey also allows us to build a food security index which is detailed in Section 3.1. What
	is original here is that the information on migration and food security is connected to a
	database on local climatic conditions. Weather centers across the country regularly
	record various rainfall

Table 3 . Results of the principal component analysis

 3

	No Rotation
		Component 1	Component 2
	Internal Faucet	0.4763	0.4120
	Existence of a separate room for cooking 0.4763	0.7959
	Cereal /Tuber / Vegetable expenditures 0.6162	-0.3048
	Meat/Fish/Egg expenditures	0.22.62	-0.3223
	Eigen Values	1.23662	1.02804
	Explained Variance	0.3092	0.2570
	Source: 2010 World Bank Survey on Migration and Remittances in Burkina Faso and
	authors' calculations

Table 4 . Descriptive statistics

 4

	Variable	Mean	Std.dev	Nb of HH	Measurement	Data Source
	Remittances	25.98	107.09	2,102	Amount of remittances	World Bank Survey on
					received by HH (divided by	Migration and Remittances in
					1000) in CFA Francs	Burkina Faso (2010)
	Rural	94%	0.25	2,102	Equals 1 if the HH lives in a	World Bank Survey on
					rural area, % of total	Migration and Remittances in
					population in the region	Burkina Faso (2010)
	Rainfall Index	0.57	0.40	2,102	Rainfall Variability since	Department of Meteorology
	(2007)				2007
	Rainfall Index	0.87	0.57	2,102	Rainfall Variability since	Department of Meteorology
	(2001)				2001
	Rainfall	0.69	0.28	2,102	Rainfall Variability during	Department of Meteorology
	Season Index				the raining season since
					2007
	Food	3 793.59	4 318.40	2,102	Per capita expenditures in	World Bank Survey on
	Expenditures				food per month in CFA	Migration and Remittances in
					Francs	Burkina Faso (2010)
	HH Head	93%		2,102	Equals 1 if the Head of HH	World Bank Survey on
	Gender				is a man, % of the total	Migration and Remittances in
					population in the region	Burkina Faso (2010)
	HH Head Age	49.50	15.89	2,099	Household Head Age, in	World Bank Survey on
					years	Migration and Remittances in
						Burkina Faso (2010)
	Literacy	1.45	1.87	2,069	Number of literate people	World Bank Survey on
					in the HH	Migration and Remittances in
						Burkina Faso (2010)
	Teenagers	1.00	1.30	2,069	Number of teenagers (15	World Bank Survey on
					years or older)	Migration and Remittances in
						Burkina Faso (2010)
	Children	1.52	1.46	2,069	Number of children under 5 World Bank Survey on
						Migration and Remittances in
						Burkina Faso (2010)
	Luminosity	2.68	10.15	1,913	Night-time luminosity	National Centre for
	Intensity				intensity	Environmental Information
	Poverty	46.18%	15.07	2,102	Population share under the	Reports of the « Institut
	Incidence				poverty line between 2008	National de la Statistique et de
					and 2010 by region	la Démographie » of Burkina
						Faso
	Migrant'	26.39%	0.44	2,102	Percentage of migrants	World Bank Survey on
	Education				with at least a primary	Migration and Remittances in
	Level				education	Burkina Faso (2010)
	Distance to	64.05	57.91	2,102	Distance between	World Bank Survey on
	Railway				households' geographical	Migration and Remittances in
					location and the railway in	Burkina Faso (2010) and
					kilometers	authors' work

Table 5 . Impact of remittances and climate variability on food security -OLS results

 5

	All HH

Table 6 . The role of remittances in the context of climate variability -OLS results on interactive term

 6

	All HHs

Table 7 . Impact of remittances and climate variability on food security -Robustness checks-OLS results

 7

	All HHs	50% of HHs receiving highest amount in remittances

  10. which has incontestably shaped the migration patterns of Burkina Faso. For instance, in the early 1930s, Burkina Faso 11 became a part of Ivory Coast as a consequence of French West African administration, while other parts of the country joined other neighboring countries (Burkina Faso subsequently recovered its original borders after independence in 1960).Between 1951 and 1955, Ivory Coast was the leading recipient country of Burkina Faso's migrants, while receiving nearly 60%

Table 8 . Impact of remittances and climate variability on food security -IV results

 8 Based on the column IV2.1 of Table8, we found that an amount of remittances of 1,284,262.30 FCFA, or USD 2,167 per household and USD 309.57 per capita is necessary annually to dampen the negative effect of rainfall variability on food security. In 2010, the World Development Indicators estimated the GDP per capita of the country at USD 592.61.

	All HH

Table 9 . Impact of remittances and climate variability on food security -Robustness checks IV results

 9 in parentheses. *** p<0.01, ** p<0.05, * p<0.1. IV1 and IV2 refer respectively to the use of 1 and two instruments. Sargan Statistic in IV2 is in parenthesis.

	All HH

Interested readers can refer to[START_REF] Barrett | Measuring food insecurity[END_REF] or[START_REF] Pinstrup-Andersen | Food security: definition and measurement[END_REF] for an extensive presentation of methodological issues pertaining to food security or insecurity measurement.

We tried to catch the availability dimension with a dummy pertaining to the possession of agricultural land. However, calculations did not give satisfactory results. The stability dimension refers to the term "at all times" of the FAO definition. It refers to the stability of the three dimensions cited above over time. Since our data has no time dimension, this aspect is not taken into account.

Cereals, milk, meat, sugar, vegetable oils, fruits, vegetables, starchy roots (Pangaribowo, Gerber and Torero, 2013).

FAO (2008) stated "Utilization is commonly understood as the way the body makes the most of various nutrients in food. Sufficient energy and nutrient intake by individuals is the result of good care and feeding practices, food preparation and diversity of the diet and intra-household distribution of food. Combined with good biological utilization of food consumed, this determines the nutritional status of individuals."

Bobo-Dioulasso, Bogandé, Boromo, Dedougou, Dori, Fada N'Gourma, Gaoua, Ouagadougou, Ouahigouya, Po.

The choice of the years to compute this index is based on the availability of the data. Therefore, the height of rain in 2001 is represented by the mean amount of rain since 1971.

There is approximately one weather station for each region in Burkina Faso. This allowed us to assign the rainfall variability index to households, according to the region they are located in.

This work was supported by the LABEX IDGM+ (ANR-10-LABX-14-01) within the program "Investissements d'Avenir" operated by the French National Research Agency (ANR).

Études et Documents are available online at: https://cerdi.uca.fr/etudes-et-documents/

Appendix

Appendix 1: Localization of surveyed villages and weather stations.

Burkina Faso is divided into 13 administrative regions, which encompass 45 provinces.

The regions observed in this survey are: Boucle du Mouhoun, Center-Est, Western-Center, Center, North-Center, North, Hauts Bassins. Provinces observed in the survey are: Banwa, Sourou, Kadiogo, Namentenga, Sanmatenga, Boulkiemde, Boulgou, Tuy, Passoré, Yatenga.