Rodrigue Imad
email: rodrigue.imad@telecom-bretagne.eu

Sebastien Houcke
email: sebastien.houcke@telecom-bretagne.eu

Christophe Jego
email: christophe.jego@telecom-bretagne.eu

Blind frame synchronization of product codes based on the adaptation of the parity check matrix

We present in this paper a blind frame synchronization method based on the adaptation of the parity check matrix of the code. The blind synchronizer is initially based on the calculation of the Log-Likelihood Ratios (LLR) of the syndrome elements, obtained using the parity check matrix of the code. Before applying our synchronization procedure, we propose in this paper to rearrange the parity check matrix of the code according to the reliability of the received symbols as previously introduced for decoding linear block codes with high density parity check matrix. Simulation results show that the Frame Error Rate (FER) curves obtained after applying the proposed synchronization method to product codes are very close to the ones with perfect synchronization. In addition to its powerful synchronization properties, the main advantage of the proposed synchronization algorithm is its capability of being introduced as a part of the decoder so that no additional material is required for the synchronization step.

I. INTRODUCTION

In most challenging digital communication systems, error correcting coding is becoming increasingly important. Several studies [START_REF] Berrou | Near shannon limit errorcorrecting coding and decoding: turbo-codes[END_REF][2] [START_REF] Pyndiah | Near optimum decoding of product codes[END_REF] have demonstrated that actual codes such as LDPC codes, turbocodes and product codes, are very powerful and are able to decode heavily corrupted sequences. However, these works were based on the assumption of coherent detection, which may be less than realistic for many digital communication systems. Conventional frame synchronization is achieved by adding to the transmitted symbols a synchronization sequence known by the receiver. This sequence is detected at the reception by running the received symbols through a correlator [START_REF] Barker | Group synchronization of binary digital systems[END_REF] [START_REF] Massey | Optimum frame synchronization[END_REF]. In order to achieve good performance on low signal to noise ratios, traditional synchronization methods should increase the length of the inserted training sequence. This reduces the spectral efficiency of the transmission especially when codes of small sizes are used. Another solution to improve the system performance is to take advantage of the code structure by considering frame synchronization jointly with the decoding as in [START_REF] Robertson | A generalized frame synchronizer[END_REF] [START_REF] Cassaro | Frame synchronization for coded systems over AWGN channels[END_REF]. Rather than placing the synchronization bits in a separate header, the authors of [START_REF] Howlader | Decoder-assisted frame synchronization for packet transmission[END_REF] propose to place them in a midamble. These bits are then encoded as part of the data sequence. We are interested in developing blind methods of frame synchronization wherein no additional sequence is added to the coded one. We have previously proposed in [START_REF] Imad | Blind frame synchronization for error correcting codes having a sparse parity check matrix[END_REF] a blind frame synchronization method that is based on a Maximum A Posteriori probability (MAP) approach in the sense of maximizing the probability that a position t corresponds to the correct synchronization moment, knowing the received samples. This method has been first introduced for a Binary Symmetric Channel (BSC) [START_REF] Houcke | Blind frame synchronization for block code[END_REF] and then generalized for a Gaussian Channel [START_REF] Imad | Blind frame synchronization on gaussian channel[END_REF]. It has been also applied in an Interleaved Division Multiple Access (IDMA) context [START_REF] Houcke | Blind detection for block interleaved division multiple access[END_REF] and it gave promising results. Applied to codes having sparse parity check matrices such as LDPC codes and convolutional codes, the previous method presents good performance. Moreover, it has been shown in [START_REF] Imad | Blind frame synchronization for error correcting codes having a sparse parity check matrix[END_REF] that this synchronization method outperforms another technique of blind frame synchronization introduced in [START_REF] Sun | Optimum frame synchronization for preamble-less packet transmission of turbo codes[END_REF]. However, these methods are not suitable for codes having a high number of nonzero elements in their parity check matrix, case of linear block codes as Bose-Chaudhuri-Hocquenghem (BCH) codes, Reed-Solomon (RS) codes and product codes. A decoder using the Belief Propagation (BP) algorithm can be used for decoding linear block codes. This algorithm is considered to be the reference decoding algorithm of LDPC codes having a sparse parity check matrix. However, it is not applied to BCH codes or RS codes, for which the parity check matrix is not sparse. A modified version of this algorithm has been introduced in [START_REF] Jiang | Iterative soft-input-soft-output decoding of reed-solomon codes by adapting the parity check matrix[END_REF] (Adaptive Belief Propagation, ABP) for RS codes and modified in [START_REF] Jego | Turbo decoding of product codes based on the modified adaptive belief propagation algorithm[END_REF] (m-ABP) for BCH and product codes, where the authors propose an adaptation step of the parity check matrix of the code according to the reliability of the received symbols. In this paper, we use the general idea of the above modified decoding algorithm and propose a new blind frame synchronization method especially adapted for product codes. This paper is organized as follows. Section II briefly presents product codes and the m-ABP decoding algorithm proposed in [START_REF] Jego | Turbo decoding of product codes based on the modified adaptive belief propagation algorithm[END_REF]. In Section III we introduce the proposed method of blind frame synchronization of BCH codes and BCH product codes. Simulation results are presented in Section IV. Finally, Section V concludes the work.

II. PRODUCT CODES AND THE M-ABP ALGORITHM

Being first introduced by Elias in 1954 [START_REF] Elias | Error-free coding[END_REF], a product code is a multidimensional code constructed from elementary codes. Let us consider two systematic linear block codes C 1 (n

k 2 × k 1 n 1 C 1 and C 2 C 2 (n 2 , k 2 ) C 1 (n 1 , k 1 )
Fig. 1. Product Code constructed from two systematic linear block codes encoded by encoder C 1 . As a result, k 2 codewords of length n 1 bits each are obtained and placed in a two-dimensional vector. Each column of this vector is then encoded by encoder C 2 to produce a codeword of length n 2 . The final result is a product code of length n 1 × n 2 and dimension k 1 × k 2 . Note that the dimension of a code represents the length of the data block contained in this code. Product codes are usually decoded by the Chase-Pyndiah algorithm [START_REF] Pyndiah | Near optimum decoding of product codes[END_REF]. It is a turbo-like decoding algorithm where the rows and columns decoders of the product code exchange extrinsic information on the bits. In [START_REF] Jiang | Iterative soft-input-soft-output decoding of reed-solomon codes by adapting the parity check matrix[END_REF], the authors propose the ABP algorithm for decoding RS codes. This method adapts the parity check matrix at each iteration of the BP algorithm according to the reliabilities of the received symbols, in order to sparsify the columns of the parity check matrix associated with the least reliable bits. The ABP algorithm being very complex to implement, a modified version (m-ABP) was proposed by Jego and Gross in [START_REF] Jego | Turbo decoding of product codes based on the modified adaptive belief propagation algorithm[END_REF]. The m-ABP algorithm applied to BCH product codes is presented in the following paragraph. First of all, the symbols of each row (column) of the received product code are rearranged according to their reliability. In other words, we order these symbols by their absolute values. Then, the n r columns of H corresponding to the n r least reliable symbols are reduced to obtain an identity squared matrix. This is done by applying the Gaussian elimination method. The aim of this procedure is to reduce the number of nonzero elements in the part of the parity check matrix that is associated to the least reliable symbols. The next step of the m-ABP decoding algorithm is the traditional iterative BP algorithm: each row and column of the product code is decoded by a BP algorithm where iterations are called local iterations. Rows and columns decoders exchange extrinsic information via an iterative process. Each iteration of the turbo process is called a global iteration. Finally hard decisions are computed during the last global iteration. Once applied to BCH product codes, the m-ABP algorithm outperforms the standard ABP algorithm and provides similar performance in terms of bit error rate to the classical Chase-Pyndiah algorithm [START_REF] Jego | Turbo decoding of product codes based on the modified adaptive belief propagation algorithm[END_REF]. In the next section of this paper we describe how to use a part of the above decoding algorithm in our proposed blind frame synchronization method.

III. PROPOSED METHOD OF BLIND FRAME SYNCHRONIZATION OF BCH AND PRODUCT CODES

Inspired by the m-ABP decoding algorithm, we introduce in this section a new method of blind frame synchronization to be applied to linear block codes as BCH and product codes. In this study, we consider that the transmitter is sending a binary sequence of codewords and is using a Binary Phase Shift Keying (BPSK) mapping. The propagation channel is corrupted by a quasi-static additive white Gaussian noise. For a given code of rate

R = n c -n r n c (1)
corresponds a parity check matrix H of size n r × n c , where n c represents the length of a codeword and n r the number of parity relations. Let b(i) = ±1 be the i th coded and modulated bit to be transmitted. At the reception, the i th received sample is given by:

r(i) = b(i -t 0 ) + w(i), (2)
where t 0 is an integer representing the shift of the transmitted symbols due to the delay introduced by the propagation channel and w(i) a white Gaussian noise. The received sequence of N samples can now be written as:

r = [r(1), . . . , r(N )]. (3)
The main target of frame synchronization is to find the position of a codeword in the received sequence. In other words, we have to estimate the delay t 0 that we assume (without loss of generality) to be lower than n c . Let us consider a BCH code of length n c bits. In order to apply the blind frame synchronization procedure, we consider a sliding synchronization window of length Kn c . Fig. 2 shows three different positions for the sliding window corresponding to t = 0, 1 and t 0 . At a position t and for each block of size n c contained in the sliding window, we order its symbols according to their reliabilities and adapt the corresponding parity check matrix. Once this operation is done, we calculate the vector of Log-Likelihood Ratios (LLR) of the syndrome elements. This vector is written as:

L(S t ) = [L(S t (1)), . . . , L(S t (Kn r ))], (4)
where L(S t (k)) is the LLR of the k th syndrome element.

According to [START_REF] Hagenauer | Iterative decoding of binary block and convolutional codes[END_REF], L(S t (k)) is proportional to: j th non zero element in this k th row, respectively. Having this, we compute

L(S t (k)) = (-1) u k +1
φ(t) = Knr k=1 L(S t (k)) (6)
and the frame synchronization position is estimated by: t0 = argmin t=0,...,nc-1

{ φ(t)}. (7)
In the case of product codes, we take advantage of their multidimensional structure and propose a synchronization method especially adapted for these codes. Therefore, consider a product code C(n 1 n 2 , k 1 k 2 ) constructed from two elementary systematic linear block codes C 1 (n 1 , k 1 ) and C 2 (n 2 , k 2 ). The product code being of length n c = n 1 n 2 , we consider a sliding synchronization window of length Kn 1 n 2 . For each block of size n 1 n 2 contained in the sliding window, we divide the proposed synchronization procedure into two parts. First of all, we arrange the symbols in each row of the product code according to their reliabilities. Each permuted row causes the adaptation of the parity check matrix of code C 1 , as explained in the previous section. Then, for each row of the received product code we calculate the LLR of the syndrome elements as in (5) by using the adapted parity check matrix of code C 1 . Let φ1 (t) be the sum of these syndrome elements. Each column of the product code being a codeword of C 2 , the second part of the proposed synchronization procedure is the same as the previous one but applied this time to the columns of the received code. The result is φ2 (t), sum of the syndrome elements of the code columns, obtained using the adapted parity check matrix of code C 2 . Finally, we calculate a new criterion for the proposed method:

φp (t) = φ1 (t) + φ2 (t) (8)
and the frame synchronization position is estimated by:

t0 = argmin t=0,...,nc-1 { φp (t)}. (9)
In addition to its powerful synchronization properties, the advantage of the above synchronization algorithm is its capability of being presented as a part of the m-ABP decoder. Indeed, once the parity check matrix of the component codes is rearranged for the synchronization procedure, it can be directly used by the m-ABP decoder. Furthermore, the calculation of (5) used for synchronization is equivalent to the first half iteration of the m-ABP algorithm. Therefore, using the above synchronization method for product codes does not require any additional materials then the ones initially used for decoding. The performance of the proposed synchronization method is evaluated in the next section of this paper.

IV. SIMULATION RESULTS

In order to study the performance of our synchronization method, we estimated the probability of false synchronization. The evaluation of this probability is realized by Monte Carlo simulation where for each configuration, the noise, information bits and the delay of the channel were randomly chosen. In the case of cyclic codes and in order to keep the good performance of our synchronization technique, a pseudorandom interleaver should be used to permute the transmitted symbols. This interleaver should be known by the receiver so that the cyclic property of the code is retrieved after the synchronization procedure. Furthermore, the size of the synchronization window should be multiple of the interleaver length. Let us designate by "existing method" the blind synchronization method proposed in [START_REF] Imad | Blind frame synchronization for error correcting codes having a sparse parity check matrix[END_REF]. Fig. 3 shows a comparison between the proposed and existing synchronization methods /N 0 (dB) Probability of false synchronization existing method, K=1 block proposed method, K=1 block existing method, K=2 blocks proposed method, K=2 blocks Fig. 4. Comparison between the proposed and existing methods applied to the (32, 26) 2 BCH product code. once applied to the extended BCH (32, 26) code. For a synchronization window of size K = 1 block, it is clear that both synchronization methods do not present good performance. This is due to the small size of the code (32 bits) and the low number of parity equations (6 equations). However and as shown in [START_REF] Houcke | Blind frame synchronization for block code[END_REF], the probability of false synchronization decreases with the length of the synchronization window K.

For K = 5 blocks and at a probability of false synchronization equal to 10 -3 , a gap of 2 dB is observed between the existing and proposed synchronization methods.

In the remaining of this paper, the only difference between the "existing" and "proposed" methods is the adaptation step of the parity check matrix to the symbols reliability. Consider now the (32, 26) 2 BCH product code. This notation means that the product code C is constructed from two identical (32, 26) extended BCH codes. Fig. 4 shows a comparison between the existing synchronization method and the proposed one. For the same length of the synchronization window, it is clear that the proposed method outperforms the existing one. A gain of around 1.3 dB is achieved at a probability of false synchronization equal to 10 -3 . Fig. 5 shows the performance of the proposed method applied to the (16, 11) 2 and the (32, 26) 2 BCH product codes. Although the (16, 11) 2 has 8 non zero elements in each line of H and the (32, 26) 2 has 16, the latter presents better performance for E b /N 0 greater than 1.5 dB. This is due to the fact that code (32, 26) 2 is longer than code (16, 11) 2 (1024 bits instead of 256) and has a greater number of parity check equations (6 instead of 5). In this same figure, we also compared our results to the ones obtained with Massey's synchronization approach, which locates a synchronization word periodically embedded in the binary data [START_REF] Massey | Optimum frame synchronization[END_REF]. Even for a synchronization word of length L = 20 bits, our proposed method converges quicker than the one introduced by Massey. For the (32, 26) 2 product code and at a probability of false synchronization equal to 10 -3 , there is a gap of around 2 dB between the proposed method (K = 1 block) and the existing synchronization method of Massey (L = 20 bits).

In order to evaluate the robustness of the proposed synchronization method, we plotted the Frame Error Rate (FER) curves obtained by decoding product codes using the m-ABP algorithm, which is applied after achieving the blind frame synchronization step. For the m-ABP decoder, three local iterations and eight global iterations were done. Fig. 6 shows the FER curves obtained after decoding the (16, 11) 2 BCH product code. It is clear that the existing synchronization method is not suitable for product codes. However, a gap of only 0.6 dB is observed between the FER curves obtained after applying the proposed synchronization method (K = 1 block) and the ones of the perfect synchronization case. Furthermore, when K = 2 blocks and for E b /N 0 greater than 1.5 dB, the curves of FER for the proposed method are almost the same as the ones obtained in the case of perfect synchronization.

In the case of the (32, 26) 2 BCH product code, Fig. 7 shows that even for K = 1 block, the FER curves obtained after applying the proposed synchronization method are the same as the ones of the prefect synchronization case.

V. CONCLUSION

In this paper, we have proposed a blind frame synchronization method based on the adaptation of the parity check matrix of the code. The proposed synchronization method clearly outperforms an existing method of blind frame synchronization previously introduced. Once the proposed synchronization method is applied to BCH product codes, simulation results have shown that the frame error rate curves obtained after decoding were almost the same as the ones of the perfect synchronization case. Another advantage of the proposed method is its capability of introducing the blind synchronizer as a part of the m-ABP decoder so that no additional material is needed for the synchronization process.

Fig. 2 .

 2 Fig. 2. Blind frame synchronization principle.

Fig. 3 .

 3 Fig. 3. Comparison between the proposed and existing methods applied to the extended BCH (32, 26) code.

Fig. 5 .

 5 Fig.5. The proposed synchronization method applied to the (16, 11) 2 and (32, 26) 2 BCH product codes and compared to Massey's method.

  1 , k 1 ) and C 2 (n 2 , k 2 ). Fig 1 shows the implementation of the product code C(n 1 n 2 , k 1 k 2 ). k 2 data blocks of length k 1 bits each, are

	Information Block	Redundancy due to
		n 2
	Redundancy	Redundancy
	due to	due to

  Fig. 6. Frame Error Rate of the m-ABP decoder applied to the (16, 11) 2 BCH product code.Fig. 7. Frame Error Rate of the m-ABP decoder applied to the (32, 26) 2 BCH product code.

		10 0
		10 -1
	FER	FER
		10 -2
	perfect synchronization			perfect synchronization
	existing method, K=1 block			existing method, K=1 block
	proposed method, K=1 block			proposed method, K=1 block
	existing method, K=2 blocks			existing method, K=2 blocks
	proposed method, K=2 blocks	10 -3	1	1.5 proposed method, K=2 blocks 2 2.5	3	3.5	4
	N 0	(dB)		E b /N 0	(dB)


Richard Huaman Ramirez

Noël Albert

Dwight Merunka

Are global brands trustworthy? The role of brand affect, brand innovativeness, and consumer ethnocentrism

Introduction

Multinational companies essentially manage their brands globally (e.g. Red Bull, Coca-Cola, Louis Vuitton), mainly because consumers tend to have similar tastes, preferences, and expectations around the world [START_REF] Hassan | Global market segmentation strategies and trends[END_REF][START_REF] Steenkamp | How perceived brand globalness creates brand value[END_REF]. Yet, in recent years, occurred an increase of consumers' anti-globalization feelings as expressed in popular votes such as in the US ("America first") or the UK (the Brexit vote), and in a growing political support towards European nationalist parties (e.g. Italy, Poland, Hungary, Austria, Slovakia, Bulgaria) [START_REF] Hale | Why is the anti-global backflash happening now?[END_REF]. Specifically, in France, a growing number of voters support the nationalist party which defends antiglobalization and protectionist policies [START_REF] Beard | French voters increasingly question globalization[END_REF]. This recent tendency is relevant to both academics and practitioners who study or manage global brands, and a revised understanding of the effects of perceived brand globalness (PBG) on consumer behavior is warranted.

PBG is consumers' understanding that brands are present in multiple countries with generally the same name, symbols, and products [START_REF] Steenkamp | How perceived brand globalness creates brand value[END_REF], global brands being recognized universally in a direct or an indirect way [START_REF] Dimofte | Global brands in the United States: how consumer ethnicity mediates the global brand effect[END_REF]. Consumers recognize global brands directly during international travel, or indirectly through media exposure or word-of-mouth, with brand information linked to international presence. These brands also use language, aesthetic styles, and story themes as cultural symbols to position themselves as global [START_REF] Akaka | Global brand positioning and perceptions: international advertising and global consumer culture[END_REF][START_REF] Alden | Brand positioning through advertising in Asia, North America, and Europe: the role of global consumer culture[END_REF]. In fact, brands do not need to exist worldwide to be global, implying their "globalness" through marketing communications [START_REF] Alden | Brand positioning through advertising in Asia, North America, and Europe: the role of global consumer culture[END_REF][START_REF] Harris | European challenge: developing global organizations[END_REF][START_REF] Steenkamp | How perceived brand globalness creates brand value[END_REF].

Past research demonstrates that PBG has positive consequences on multiple judgments, relationships and behaviors such as brand quality [START_REF] Akram | Perceived brand globalness in emerging markets and the moderating role of consumer ethnocentrism[END_REF][START_REF] Mohan | Perceived globalness and localness in B2B brands: a co-branding perspective[END_REF][START_REF] Özsomer | The interplay between global and local brands: a closer look at perceived brand globalness and local iconness[END_REF][START_REF] Steenkamp | How perceived brand globalness creates brand value[END_REF][START_REF] Xie | An extended model of preference formation between global and local brands: the roles of identity expressiveness, trust, and affect[END_REF], brand prestige [START_REF] Akram | Perceived brand globalness in emerging markets and the moderating role of consumer ethnocentrism[END_REF][START_REF] Özsomer | The interplay between global and local brands: a closer look at perceived brand globalness and local iconness[END_REF][START_REF] Steenkamp | How perceived brand globalness creates brand value[END_REF][START_REF] Xie | An extended model of preference formation between global and local brands: the roles of identity expressiveness, trust, and affect[END_REF], brand attitude [START_REF] Davvetas | The impact of perceived brand globalness on consumers' willingness to pay[END_REF][START_REF] Halkias | The interplay between country stereotypes and perceived brand globalness/localness as drivers of brand preference[END_REF][START_REF] Winit | Global vs. local brands: how home country bias and price differences impact brand evaluations[END_REF], functional-psychological value of products [START_REF] Swoboda | Does being perceived as global pay off? An analysis of leading foreign and domestic multinational corporations in India, Japan, and the United States[END_REF], brand purchase likelihood [START_REF] Steenkamp | How perceived brand globalness creates brand value[END_REF][START_REF] Winit | Global vs. local brands: how home country bias and price differences impact brand evaluations[END_REF], and willingness to pay [START_REF] Davvetas | The impact of perceived brand globalness on consumers' willingness to pay[END_REF].

PBG is also positively related to brand trust as evidenced in different countries such as the US, Nepal, or China [START_REF] Atilgan | Customer-based brand equity for global brands: a multinational approach[END_REF][START_REF] Rosenbloom | Country-of-origin effects and global brand trust: a first look[END_REF][START_REF] Xie | An extended model of preference formation between global and local brands: the roles of identity expressiveness, trust, and affect[END_REF]. However, two of these studies were published a decade ago before the rise of anti-global and nationalist values and movements [START_REF] Hale | Why is the anti-global backflash happening now?[END_REF]. Therefore, questioning whether this relationship still holds, whether it holds for all consumers, and what is the process explaining the relationship between PBG and brand trust are the main research objectives pursued here.

Understanding this relationship is important since recent professional studies reveal a major decline in consumer trust explained by the fact that consumers are reluctant to globalization (Edelman Trust Barometer, 2015, 2017) and because brand trust is seen as a major component of consumer-brand relationships [START_REF] Albert | A synthesis of the consumer-brand relationship domain: using text mining to track research streams, describe their emotional associations, and identify future research priorities[END_REF][START_REF] Chaudhuri | The chain of effects from brand trust and brand affect to brand performance: the role of brand loyalty[END_REF]. Therefore, measuring the effect of PBG on brand trust and understanding the process of such an influence is relevant to academics and practitioners. [START_REF] Xie | An extended model of preference formation between global and local brands: the roles of identity expressiveness, trust, and affect[END_REF] contrast local and global brands in China and establish that brand trust is the most influential factor explaining preference formation. Global brands are perceived as more innovative and exciting than other brands [START_REF] Dimofte | Cognitive and affective reactions of US consumers to global brands[END_REF][START_REF] Dimofte | Global brands in the United States: how consumer ethnicity mediates the global brand effect[END_REF], and brand innovativeness and brand intimacy influence brand trust [START_REF] Srivastava | Antecedents and moderators of brand trust in the context of baby care toiletries[END_REF]. Therefore, the relationship between PBG and brand trust may be explained by brand innovativeness and brand affect. However, we argue that the strength of the relationships between these concepts may depend on consumer ethnocentrism since ethnocentric consumers do not have a positive perception of global brands [START_REF] Klein | The animosity model of foreign product purchase: an empirical test in the People's Republic of China[END_REF][START_REF] Shimp | Consumer ethnocentrism: construction and validation of the CETSCALE[END_REF][START_REF] Siamagka | Revisiting consumer ethnocentrism: review, reconceptualization, and empirical testing[END_REF]. We propose consumers' ethnocentrism as a moderating variable of the above relationships, particularly since ethnocentrism is revived by the recent economic downturn in Western countries [START_REF] Balabanis | Inconsistencies in the behavioural effects of consumer ethnocentrism: the role of brand, product category and country of origin[END_REF], and by vivid antiglobal movements and nationalism across most countries.

In the current research, we therefore study how global brands may positively influence brand trust through the mediation of brand affect and brand innovativeness, and test the moderating role of consumer ethnocentrism in the relationship between PBG and both brand affect and brand innovativeness.

Conceptual framework and hypotheses

Brand trust

Brand trust refers to the expectation that consumers have about a brand and particularly that the brand will consistently accomplish its promise and deliver value for the benefit of the consumer, and for the least, not perniciously [START_REF] Doney | An examination of the nature of trust in buyer-seller relationships[END_REF][START_REF] Mayer | An integrative model of organizational trust[END_REF]. It is a major dimension of consumers' relationships with brands since it influences brand equity (Delgado-Ballester and Munuera-Alemán, 2005), brand loyalty [START_REF] Chaudhuri | The chain of effects from brand trust and brand affect to brand performance: the role of brand loyalty[END_REF][START_REF] Delgado-Ballester | Brand trust in the context of consumer loyalty[END_REF]Frasquet et al., 2017;[START_REF] Huang | The impacts of brand experiences on brand loyalty: mediators of brand love and trust[END_REF][START_REF] Menidjel | Examining the moderating role of personality traits in the relationship between brand trust and brand loyalty[END_REF][START_REF] Sung | Effects of brand personality on brand trust and brand affect[END_REF][START_REF] Veloutsou | Brand evaluation, satisfaction and trust as predictors of brand loyalty: the mediator-moderator effect of brand relationships[END_REF], brand commitment [START_REF] Ha | Factors influencing consumer perceptions of brand trust online[END_REF][START_REF] Morgan | The commitment-trust theory of relationship marketing[END_REF], and purchase intentions [START_REF] Bhandari | What does the brand say? Effects of brand feedback to negative eWOM on brand trust and purchase intentions[END_REF][START_REF] Sichtmann | An analysis of antecedents and consequences of trust in a corporate brand[END_REF].

Trust is composed of three dimensions: integrity, benevolence, and ability [START_REF] Mayer | An integrative model of organizational trust[END_REF][START_REF] Schoorman | An integrative model of organizational trust: past, present, and future[END_REF]. Integrity refers to the favorable values that the trustor adheres to during the exchange with the trustee, and when the trustee promises benefits to the trustor, the former is evaluated through the sincerity and honesty of his or her words [START_REF] Gurviez | Proposition d'une échelle de mesure multidimensionnelle de la confiance dans la marque[END_REF].

Benevolence involves the positive intentions of the trustee. The trustor evaluates if the trustee genuinely wants to do good to him or her, shows concern about his or her welfare [START_REF] Doney | An examination of the nature of trust in buyer-seller relationships[END_REF], and avoids an egocentric motivation for making profit off of the trustor [START_REF] Mayer | An integrative model of organizational trust[END_REF].

Finally, ability is related to the capacity or competence of the trustee in order to respond to the needs of the trustor [START_REF] Delgado-Ballester | Brand trust in the context of consumer loyalty[END_REF][START_REF] Mayer | An integrative model of organizational trust[END_REF], its ability to accomplish promises, and ability to perform stated functions or services [START_REF] Chaudhuri | The chain of effects from brand trust and brand affect to brand performance: the role of brand loyalty[END_REF].

The mediating role of brand affect in the relationship between PBG and brand trust

Brand affect refers to "a brand's potential to elicit a positive emotional response in the average consumer as a result of its use" (Chaudhuri and Holbrook, 2001, p. 82). Thus, consumers with high brand affect perceive that brands make them happy, joyful, and affectionate.

We propose that the relationship between PBG and brand trust is mediated by brand affect for two reasons. First, brands perceived as global elicit positive brand affect since consumers generally like to be a part of an aspiring global consumer culture and being a citizen of the world [START_REF] Alden | Brand positioning through advertising in Asia, North America, and Europe: the role of global consumer culture[END_REF][START_REF] Holt | How global brands compete[END_REF]. In addition, consumers generally esteem global brands [START_REF] Johansson | The esteem of global brands[END_REF], considering them to be more exciting and stylish [START_REF] Dimofte | Cognitive and affective reactions of US consumers to global brands[END_REF][START_REF] Dimofte | Global brands in the United States: how consumer ethnicity mediates the global brand effect[END_REF] and providers of emotional value (Swoboda et al., 2012;[START_REF] Swoboda | Does being perceived as global pay off? An analysis of leading foreign and domestic multinational corporations in India, Japan, and the United States[END_REF]. Therefore, PBG may engender positive emotional responses.

Second, brand affect positively influences brand trust since "affective attachments form the basis for caring and benevolent actions that build trust" (Williams, 2001, p. 379). Trustors who perceive an emotional investment of caring for, and benevolence towards the trustee feel the deepest level of trust [START_REF] Rempel | Trust in close relationships[END_REF]. In this sense, brands that render consumers joyful are perceived as trustable. For instance, consumers trust more fast-moving consumer goods brands when they perceive them as providing more feelings and emotions [START_REF] Singh | Does having an ethical brand matter? The influence of consumer perceived ethicality on trust, affect and loyalty[END_REF]. In addition, affective reactions positively influence the judgment of trust [START_REF] Dunn | Feeling and believing: the influence of emotion on trust[END_REF][START_REF] Lu | What are the determinants of interpersonal trust in dyadic negotiations? Meta-analytic evidence and implications for future research[END_REF][START_REF] Williams | In whom we trust: group membership as an affective context for trust development[END_REF], a relation based on the theory proposing that individuals who are in a positive affective state evaluate other individuals and past events more favorably [START_REF] Schwarz | Feelings as information: Informational and motivational functions of affective states[END_REF][START_REF] Schwarz | How do I feel about it? Informative functions of affective states[END_REF]. Therefore, consumers' emotional response to brands perceived as global may lead to more positive affect, and in turn, to brand trust.

Based on these arguments, we propose: H1: The positive link between brand globalness and brand trust is mediated by brand affect.

The mediating role of brand innovativeness in the relationship between PBG and brand trust

Innovativeness relates to the useful and impactful properties of new elements or products and to their ability to generate a discontinuity in the marketing process [START_REF] Garcia | A critical look at technological innovation typology and innovativeness terminology: a literature review[END_REF]. It includes both newness and usefulness. From a consumer's perspective, we define brand innovativeness as the perceived ability of a brand to provide new and useful offerings to fulfill consumer needs [START_REF] Brexendorf | Leveraging the corporate brand: the importance of corporate brand innovativeness and brand architecture[END_REF][START_REF] Eisingerich | Drivers of brand commitment: a cross-national investigation[END_REF].

Brand innovativeness may mediate the relationship between PBG and brand trust. On the one hand, since global brands must obtain sustainable competitive advantages in order to become global [START_REF] Van Gelder | Global brand strategy[END_REF], innovation is centrally prioritized in their brand strategy [START_REF] Weerawardena | Conceptualizing accelerated internationalization in the born global firm: a dynamic capabilities perspective[END_REF]. If a brand is successful in its global reach, it must deliver innovative products [START_REF] Aaker | Leveraging the corporate brand[END_REF], and global brand geographical extension reinforces the perception of brand innovativeness [START_REF] Van Gelder | Global brand strategy[END_REF]. Therefore, consumers may associate global brands with the fact of being innovative and up-to-date [START_REF] Dimofte | Cognitive and affective reactions of US consumers to global brands[END_REF]2010).

On the other hand, the perceived ability of brands to generate new and useful products may influence consumers' trust. Since brand innovativeness is commonly characterized by better product performance and added valuable features [START_REF] Aaker | Innovation: brand it or lose it[END_REF], a perception of innovativeness positively influences brand trust [START_REF] Srivastava | Antecedents and moderators of brand trust in the context of baby care toiletries[END_REF][START_REF] Srivastava | Determinants of brand trust in high inherent risk products: the moderating role of education and working status[END_REF] and credibility [START_REF] Aaker | Leveraging the corporate brand[END_REF]. Brands perceived as having the competence to provide new and useful products are expected to offer better-performing products and are therefore trustable [START_REF] Kunz | How does perceived firm innovativeness affect the consumer?[END_REF]. Likewise, brands with an innovative image appear to be more expert than others, which consequently increases trust [START_REF] Keller | The impact of corporate marketing on a company's brand extensions[END_REF][START_REF] O'cass | An e-retailing assessment of perceived website-service innovativeness: Implications for website quality evaluations, trust, loyalty and word of mouth[END_REF]. Therefore, we propose: H2: The positive link between brand globalness and brand trust is mediated by brand innovativeness.

The moderating role of consumer ethnocentrism

Consumer ethnocentrism refers to "the beliefs held by consumers about the appropriateness, indeed morality, of purchasing foreign-made products" (Shimp and Sharma, 1987, p. 280). Thus, ethnocentric consumers prefer domestic products rather than foreign products because they believe that products from their own country are the best [START_REF] Klein | The animosity model of foreign product purchase: an empirical test in the People's Republic of China[END_REF], and because domestic products represent intra-cultural objects that become recipients of pride and attachment [START_REF] Herche | Ethnocentric tendencies, marketing strategy and import purchase behaviour[END_REF]. Ethnocentric consumers develop a negative attitude toward foreign products because they consider that purchasing them represents an unpatriotic act, and that it can be dangerous for the national economy, with a loss of jobs in the local labor market [START_REF] Kaynak | Consumer perceptions of foreign products: An analysis of productcountry images and ethnocentrism[END_REF]. Given that ethnocentric individuals tend to reject symbols and values that are different from their own [START_REF] Herche | Ethnocentric tendencies, marketing strategy and import purchase behaviour[END_REF], they are less cosmopolitan and less open to foreign cultures. In our context, global brands may be viewed as a threat to national economic prosperity and may represent both an economic and a cultural threat.

We argue that the effect of brand globalness on both brand affect and brand innovativeness depends on the level of ethnocentrism of consumers. Since ethnocentric consumers perceive products and symbols from their own country as the best [START_REF] Klein | The animosity model of foreign product purchase: an empirical test in the People's Republic of China[END_REF][START_REF] Siamagka | Revisiting consumer ethnocentrism: review, reconceptualization, and empirical testing[END_REF], innovativeness of global brands might not be valued, and global brand's ability to satisfy consumer needs underestimated. By contrast, non-ethnocentric consumers perceive the worldwide reach of global brands as a competitive advantage and value their innovativeness. Also, ethnocentric consumers might not feel any positive affect for global brands because they prefer domestic products, and global brands may even generate negative affect [START_REF] Shimp | Consumer ethnocentrism: construction and validation of the CETSCALE[END_REF]. They do not share a global consumer culture, and the fact that a brand is global does not generate joy or pleasure. By contrast, non-ethnocentric consumers open to the world and to global brands may experiment positive affect because global brands are in accordance with their self-concept.

It follows:

H3a: Consumer ethnocentrism negatively moderates the positive relationship between brand globalness and brand affect.

H3b: Consumer ethnocentrism negatively moderates the positive relationship between brand globalness and brand innovativeness.

The overall theoretical framework appears in Figure 1.

------------------------ Figure 1 about here ------------------------

Research methodology

Data collection and sample

Data were collected online following a two-step process. One hundred and twenty-six individuals, mainly students, willingly participated in the first data collection conducted at a business school in southern France, through a snowball method. Then, in order to obtain a larger sample, a second data collection used several student Facebook groups at a University in southern France. One hundred and twenty-four respondents, mainly students, participated in prize drawings of €50 and €20. After removing duplicates, we ended up with a final sample of 243 respondents. In order to avoid a collection method bias, we analyzed the influence of the type of collection method (snowball versus incentive) on the different variables. Based on ANOVA analyses, 1 no differences were found (p>.05), except for brand globalness, which is explained by the fact that individuals in the first collection principally selected McDonald's as the brand to be evaluated, a brand broadly acknowledged as global. In this sense, the variation of brand globalness was expounded by brand choice and not because of an effect of collection methods.

Participants were asked to complete a self-administered questionnaire based on a crosssectional design. First, they chose one brand from a list of the four most popular fast-food restaurants in France: McDonald's, Subway, and KFC (global brands), and Quick, a leading European fast food brand. The presence of a non-global brand (Quick) ensures variance in brand globalness perceptions.

We collected data concerning brand globalness, brand affect, brand innovativeness, and brand trust. 1 The assumptions for ANOVA were verified: (1) no significant outliers were detected; (2) dependent variables were (quasi) normally distributed according to [START_REF] Field | Discovering Statistics Using IBM SPSS Statistics[END_REF] (skewness and kurtosis between -2 and +2); and (3) there was homogeneity of variances for all variables except for brand globalness. For the latter variable, the Welch's ANOVA test was performed.

We added service quality as a control variable because of the nature of the restaurants and of a possible effect on the independent variable (brand trust). Finally, we collected data on ethnocentrism, and demographics.

The profile of respondents is shown in Table 1. A young sample was preferred because consumers in this age range are highly familiar with fast-food restaurants [START_REF] Gallup | Fast food still major part of US diet[END_REF]. Likewise, they are most likely to be susceptible to both positive and negative aspects of globalization [START_REF] Devecchio | Les nouveaux enfants du siècle. Djihadistes, identitaires, réacs: enquête sur une génération fracturée[END_REF][START_REF] Jin | The relationship between consumer ethnocentrism, cosmopolitanism and product country image among younger generation consumers: the moderating role of country development status[END_REF][START_REF] Shukla | Impact of interpersonal influences, brand origin and brand image on luxury purchase intentions: measuring interfunctional interactions and a cross-national comparison[END_REF].

- ----------------------- -----------------------

Measures

For each construct, existing scales were adapted from past research. A bilingual academic expert translated the questionnaire and assessed content validity of each item. The response format and the clarity of instructions of the questionnaire were then evaluated through a face-to-face interview with four students, all frequent consumers of fast food. All items were rated on a seven-point Likert scale from 1 ("strongly disagree") to 7 ("strongly agree").

Brand globalness was measured with a scale based on [START_REF] Steenkamp | How perceived brand globalness creates brand value[END_REF]. The dependent variable, brand trust, was measured through the three-dimensional scale (credibility, integrity, and benevolence) from [START_REF] Gurviez | Proposition d'une échelle de mesure multidimensionnelle de la confiance dans la marque[END_REF]. Three items developed by [START_REF] Chaudhuri | The chain of effects from brand trust and brand affect to brand performance: the role of brand loyalty[END_REF] were employed to measure brand affect, and brand innovativeness comprises three items from [START_REF] Eisingerich | Drivers of brand commitment: a cross-national investigation[END_REF]. Consumer ethnocentrism was measured using five items adapted from [START_REF] Shimp | Consumer ethnocentrism: construction and validation of the CETSCALE[END_REF]. Finally, service quality (control variable) was measured through four items adapted from [START_REF] Ekinci | The validation of the generic service quality dimensions: an alternative approach[END_REF].

Results

Confirmatory factor analysis (CFA) was first performed to examine the reliability and validity of the constructs. To evaluate the measurement model fit, three types of fit indices (absolute, incremental, and parsimonious) were used, following the suggestions of [START_REF] Jackson | Reporting practices in confirmatory factor analysis: an overview and some recommendations[END_REF]. The measurement model exhibited adequate fit, with a chi-square (χ ² )/df statistic of 1.95 (p<.01); CFI = 0.96; GFI = 0.86; IFI = 0.95; RMSEA = 0.067. To test for convergent validity, factor loadings, along with the average variance extracted (AVE), were calculated for each latent variable (Table 2). The values of composite reliabilities for all eight constructs were higher than the recommended limit of .7, and the AVE equaled or exceeded the value of .5 [START_REF] Fornell | Evaluating structural equation models with unobservable variables and measurement error[END_REF], which suggests that the measures used are internally consistent. Standardized factor loadings exceeded the .5 threshold as recommended by [START_REF] Anderson | Structural equation modeling in practice: a review and recommended two-step approach[END_REF]. The discriminant validity of the constructs is supported because their AVE values are greater than their squared correlations [START_REF] Fornell | Evaluating structural equation models with unobservable variables and measurement error[END_REF].

-------------------------Table 2 about here ------------------------An ordinary least squares (OLS) path analysis [START_REF] Hayes | Introduction to Mediation, Moderation, and Conditional Process Analysis: A Regression-Based Approach[END_REF] was then conducted in order to test the mediating and moderating effects. We first transformed the latent variables into factor scores by the sum scores method [START_REF] Distefano | Understanding and using factor scores: considerations for the applied researcher[END_REF]. In addition, the scores were averaged to reflect the scale metric. This method is advantageous because of the simple calculation and interpretation of scores and is acceptable given that the items of each latent variable present similar weight and great composite reliability value [START_REF] Distefano | Understanding and using factor scores: considerations for the applied researcher[END_REF]. Then, assumptions for using OLS path analysis were verified: (1) the dependent variable was considered as continuous because the average score of items consisted of a large number of possible values [START_REF] Nunnally | Psychometric Theory[END_REF]; (2) the independence of observation was verified through a Durbin-Watson value of 2.01, which indicates almost no auto-correlation in residuals according to [START_REF] Field | Discovering Statistics Using IBM SPSS Statistics[END_REF]; (3) the absence of multicollinearity was verified by the fact that the magnitude of the VIF (Variance Inflation Factor) on each variable was lower than 3 [START_REF] Field | Discovering Statistics Using IBM SPSS Statistics[END_REF]; and finally (4) no significant outliers were found in the data. toward brands and perceive them as more innovative trust these brands more. Second, through a parallel mediation analysis [START_REF] Hayes | Introduction to Mediation, Moderation, and Conditional Process Analysis: A Regression-Based Approach[END_REF]; Model 4), the bias-corrected bootstrap confidence intervals (BootLLCI to BootULCI]) based on 5,000 bootstrap samples were entirely above zero, thus validating the indirect effects of brand globalness on brand trust dimensions: integrity (0.009 to 0.075), benevolence (0.004 to 0.064), and ability (0.032 to 0.13) through brand affect, in support of hypothesis 1. In the same way, the indirect effects of brand globalness on integrity (0.003 to 0.067), benevolence (0.004 to 0.096), and ability (0.002 to 0.067) through brand innovativeness were validated, in support of hypothesis 2. The results demonstrate the mediating role of brand affect and brand innovativeness on consumer trust for global brands.

Third, a moderation analysis [START_REF] Hayes | Introduction to Mediation, Moderation, and Conditional Process Analysis: A Regression-Based Approach[END_REF]Model 8) demonstrates that the relationship between brand globalness and brand innovativeness was negatively moderated by ethnocentrism (t=-3.68, p<.001), supporting hypothesis 3a. Brand globalness is significantly related to brand innovativeness when consumer ethnocentrism is low (one SD below the mean) (b=0.295, t=3.99, p<.001) or medium (the mean) (b=0.125, t=2.06, p<.05), but not when consumer ethnocentrism is high (one SD above the mean) (b=-0.045, t=-0.54, p>.05) (see Figure 2).

------------------------Table 3 about here ------------------------------------------------Figure 2 about here ------------------------Finally, and contrary to hypothesis 3b, ethnocentrism does not moderate the relationship between brand globalness and brand affect (t=1.49, p>.05). However, we conducted a floodlight analysis [START_REF] Johnson | Tests of certain linear hypotheses and their applications to some educational problems[END_REF][START_REF] Spiller | Spotlights, floodlights, and the magic number zero: simple effects tests in moderated regression[END_REF] to identify regions of consumer ethnocentrism in which brand globalness is not related to brand affect. The analysis revealed that the relationship between brand globalness and brand affect was not significant (p>.05) among consumers whose ethnocentrism level was higher than 5.94 (0.7SD above the mean) (b JN = 0.168, t=1.97, p=.05;

see Figure 3). Therefore, consumers with very high levels of ethnocentrism (above 5.94) do not feel positive affect toward global brands, supporting hypothesis 3b.

------------------------Figure 3 about here ------------------------

Post Hoc Study

To ensure that differences of the independent variable effects are mainly based on brand globalness and not on the brand selected by participants, we analyzed the attitude of consumers towards the four fast-food brands submitted to study participants. The objective of this post hoc study is to demonstrate that the four brands are not statistically different in terms of attitude. In this case, the evaluation of brand affect, brand innovativeness and brand trust are indeed influenced by brand globalness.

We collected data through Foule Factory, a French crowdsourcing Internet marketplace that serves as a platform for recruiting and compensating individuals in online surveys. Seventy-two participants were asked to evaluate their attitude towards the four brands (McDonald's, KFC, Subway, and Quick). Attitude toward the brand was measured through three items (bad/good; negative/positive; unfavorable/favorable), adapted from [START_REF] Grossbart | Verbal and visual references to competition in comparative advertising[END_REF]. After deleting duplicate entries and individuals who did not match the required age (between 18 and 35 years old), sixty-three participants were retained (57% male, 78% of individuals with monthly household income of less than €2500, 33.3% and 30.2% of individuals were undergraduate and graduate respectively).

A proportion test allowed for a comparison between the main study population and the post hoc .479 > .05) and from Quick (sig. = .427 > .05). Similarly, the mean attitude score for Subway did not significantly differ from KFC (sig. = .137 > .05) and from Quick (sig. = .114 > .05). Therefore, brand attitude is statistically similar for the four brands and does not influence or bias the effects of brand globalness when consumers evaluated these brands.

Discussion

All hypotheses are supported by conceptual and empirical evidence. Results demonstrate the mediating role of brand affect and brand innovativeness in the relationship between PBG and brand trust. First, a mediation of brand affect partially explains the positive effect of PBG on brand trust: the more the brand is perceived as global, the more the brand elicits positive emotional responses, and in turn, the more the brand is trusted. These results are in line with past research establishing that global brands are perceived by American consumers as exciting, bearing a unique aura, and stylish [START_REF] Dimofte | Cognitive and affective reactions of US consumers to global brands[END_REF][START_REF] Dimofte | Global brands in the United States: how consumer ethnicity mediates the global brand effect[END_REF] or by Chinese consumers as providing emotional value (Swoboda et al., 2012), and that brand affect influences brand trust for Spanish consumers [START_REF] Singh | Does having an ethical brand matter? The influence of consumer perceived ethicality on trust, affect and loyalty[END_REF]. Second, the effect of PBG on brand trust is also partially mediated by brand innovativeness. A brand perceived as global is associated with a higher level of innovativeness which, in turn, influences brand trust. Our results are in line with [START_REF] Dimofte | Cognitive and affective reactions of US consumers to global brands[END_REF][START_REF] Dimofte | Global brands in the United States: how consumer ethnicity mediates the global brand effect[END_REF] with American consumers perceiving global brands as more innovative and up-to-date, and with [START_REF] Srivastava | Antecedents and moderators of brand trust in the context of baby care toiletries[END_REF][START_REF] Srivastava | Determinants of brand trust in high inherent risk products: the moderating role of education and working status[END_REF] who establish that Indian consumers trust brands because of their innovativeness.

Complementing previous studies establishing that brand prestige, brand quality, and the identity expressiveness of consumers favor consumers' evaluation of global brands [START_REF] Akram | Perceived brand globalness in emerging markets and the moderating role of consumer ethnocentrism[END_REF][START_REF] Özsomer | The interplay between global and local brands: a closer look at perceived brand globalness and local iconness[END_REF][START_REF] Steenkamp | How perceived brand globalness creates brand value[END_REF][START_REF] Xie | An extended model of preference formation between global and local brands: the roles of identity expressiveness, trust, and affect[END_REF], this research demonstrates the mediating role of both brand affect and brand innovativeness on consumer trust towards global brands.

Results also underline that the effect of PBG on brand affect and brand innovativeness are both moderated by the consumer ethnocentrism. This is in line with [START_REF] Steenkamp | How perceived brand globalness creates brand value[END_REF] who demonstrate the negative moderating role of consumer's ethnocentrism in the relationship between PBG and purchase intention in American and Korean contexts, and with [START_REF] Akram | Perceived brand globalness in emerging markets and the moderating role of consumer ethnocentrism[END_REF] who

show the negative interaction effect of PBG and consumer's ethnocentrism on brand quality and brand prestige in Pakistan. We extend this interaction effect to the constructs of brand affect and brand innovativeness in a developed country such as France.

Results also indicate that brand globalness explains respectively, 6.3% and 2.5% of the variance of brand affect and brand innovativeness, indicating the dominating aspect of brand affect compared to perceptions of innovativeness. This is in line with the notion that emotions play a powerful role in consumer perceptions [START_REF] Morrison | Building the service brand by creating and managing an emotional brand experience[END_REF]. Therefore, consumers more easily associate global brands with emotional experiences. However, brand innovativeness, compared to brand affect, has a higher explanatory power on the benevolence dimension of brand trust.

Providing new solutions seems therefore to be perceived as a way of caring for consumers and is appreciated by them. Likewise, compared to brand innovativeness, brand affect has a higher explanatory power on the ability dimension of brand trust. Affective responses (such as brand attachment) positively influence perceptions of the ability of brands to accomplish promises and hence fulfill consumer needs.

Regarding the relative impact of constructs, the influence of brand globalness on brand affect (r = .23) and brand innovativeness (r = .13) are comparable to the results of past research such as the relationships between brand globalness and brand identity expressiveness (r = .26, in [START_REF] Xie | An extended model of preference formation between global and local brands: the roles of identity expressiveness, trust, and affect[END_REF], between brand globalness and brand prestige (r = .30, in [START_REF] Akram | Perceived brand globalness in emerging markets and the moderating role of consumer ethnocentrism[END_REF], and between brand globalness and brand quality (r = .15 in [START_REF] Steenkamp | How perceived brand globalness creates brand value[END_REF]. Furthermore, the influence of brand innovativeness on brand trust (r = .20, r = .34, r = 24) and of brand affect on brand trust (r = .15, r = .11, r = .32) do not differ greatly from the relationship among brand prestige, brand quality, and brand identity expressiveness on brand trust (r = .25, r = .38, r = .39, respectively, in [START_REF] Xie | An extended model of preference formation between global and local brands: the roles of identity expressiveness, trust, and affect[END_REF].

Results in this research are congruent with that of related previous studies.

Conclusion

Theoretical contributions

Our contribution covers the relationship between two streams of research: global brands and consumer-brand relationships. On the one hand, this research contributes to the understanding of global brands by demonstrating that their ability to generate consumers' emotions and feelings increases brand trust. Consumers who recognize that global brands make them happy and joyful also perceive the emotional investment of caring and benevolence from these brands. Thus, brands that elicit positive emotional responses in consumers lead to a higher level of trust. Consumers tend to trust brands when they perceive them as providing more feelings and emotions. On the other hand, this research also highlights that global brands are perceived as able to provide new and betterperforming products to consumers, which is another way to increase consumer trust. Consumers tend to trust global brands more when they perceive that these brands offer innovative solutions to their needs. This perception concerns the newness of products but also the improved utility of products.

Thus, consumer trust towards global brands is not only increased by providing emotional benefits but also by enhancing the company's ability to surprise consumers with solutions and products they are not aware of. Global brands' ability to provide differentiated, attractive, and surprising products to consumers leads to a higher degree of trust.

Another contribution concerns the moderating effect of consumer ethnocentrism. The marketing literature already demonstrated its effect on the relationship between global brands and concepts such as brand prestige, brand quality, and purchase likelihood. This research enriches the scope of consumer ethnocentrism's effects by demonstrating its role on consumer affect, and on perceptions of innovativeness. From a general standpoint, pronounced consumer ethnocentrism generates negative evaluations towards global brands. We demonstrate that brand globalness is significantly related to brand innovativeness and to brand affect when consumer ethnocentrism is low or medium, but that this is not the case when consumer ethnocentrism is high.

Managerial implications

Most multinational companies market global brands and the management of such brands is a major challenge for managers. This study demonstrates the need for managers to increase the emotional and affective aspects of their global brands. For that, managers should and do create emotional communications that underline the pleasure and emotions related to global brand consumption.

Communications should also reflect the global brand values in order to favor an emotional connection between the brand and its consumers. Managers could also generate the desire to possess and consume their brands. For that, multiple communication channels may be used such as packaging, ads, online communication, and favoring frequent interactions between the global brand and consumers through online forums and brand communities. Finally, the implementation of sensorial and experiential retail stores also helps global brands to generate consumers' emotions and pleasure [START_REF] Helmefalk | Multi-sensory congruent cues in designing retail store atmosphere: Effects on shoppers' emotions and purchase behavior[END_REF]. Specifically we recommend the use of multisensory (visual but also aesthetic/gustatory/olfactory) and congruent cues to positively influence shoppers' emotions and consequently their trust in the global brand. All these actions should increase consumer emotions and feelings with a positive impact on trust. However, brand affect towards global brands has a tendency to be positive when ethnocentrism is high or medium. Therefore, communications will be efficient for these consumers, not for consumers high on ethnocentrism. Identifying consumer groups based on ethnocentrism is not an easy task. One way is through consumer involvement (e.g. belonging to brand communities and favoring this belonging), or through the use of consumer databases enabling to identify buyers of global brands in different categories. Another way is through the use of international channels of communications (e.g. satellite channels) or local channels of communications targeting global consumers (e.g. airport ads). Finally, advertising creation (including packaging) should feature the lifestyle of global consumers whatever their country of origin may be.

Brand managers should also emphasize the innovative aspects of their global brands through the launch of innovative products, current products' improvements (features, manufacturing, benefits)

or brand extensions. The more managers provide new, useful solutions to fulfill consumers' needs, the more consumers will trust global brands. This is a key strategic point of differentiation for global brands versus local brands always eager to copy developments made by global brands. Therefore, global brands will only remain perceived as innovative (favoring trust) if they innovate and differentiate from local brands. For example, the high dominance of Apple mobile phones in the US linked to its superior and constant innovation (more than 57% market share in the US in 2018) is severely challenged worldwide (where Samsung dominates with a 30.6% market share in 2018 followed by Apple, 22.0%). This is even more the case in Asia where Samsung exhibits high leadership (30.6% in 2018) followed by both Apple (12.7%) and Xiaomi (12.5%). Both the relative lack of innovation by Apple in recent years influencing the level of consumer trust, and ethnocentrism may contribute to the weaker position of Apple on the Asian market.

Limitations and future research

This study suffers from limitations that could be mitigated by further relevant research. First, we analyzed a limited number of brands, all in the fast-food category. Future studies could replicate the research using different product categories. For instance, technological brands may be perceived as more innovative when positioning themselves as being global. In the same vein, in the entertainment or travel categories, consumers may perceive global brands as more inclined to favor affective reactions. Furthermore, we considered three well-established brands as global and one brand as less global (European). Future research should consider higher variability in brand globalness or conduct a comparative analysis between global and local brands.

A second limitation concerns the participants who were principally young consumers between 18 and 35 years of age, and who are somewhat ethnocentric (Mean = 4.22). The literature in marketing suggests that older people are less susceptible to global brands given that attitudes toward domestic products generally become more favorable with age [START_REF] Bannister | UK consumers' attitudes towards imports: the measurement of national stereotype image[END_REF].

However, recent evidence also shows the increase of anti-globalization feelings among the younger population. Future research should include age as a moderating variable in order to explore differences in the evaluation of global brands. Furthermore, social-psychological (i.e., openness, collectivism, conservatism) and demographic (i.e., gender, education, income) factors could also be considered as moderating variables in the relationship between brand globalness and brand trust.

A third limitation is the fact that a unique bilingual expert translated the questionnaire which may explain the low levels of standardized loading for some items. Future research should use the back-translation technique in order to improve the psychometric properties of the scales. Fourth, the slight over-representation of women (62.1%) in the main study may have enhanced the moderating effect of consumer ethnocentrism, since women tend to be more ethnocentric than men [START_REF] Josiassen | Consumer ethnocentrism and willingness to buy: Analyzing the role of three demographic consumer characteristics[END_REF]. Future research should analyze samples equally represented in terms of gender in order to avoid any potential bias or formally contrast results across genders. Finally, an interesting research direction is to consider an integrative model including the two variables tested here (affect and innovativeness) and other relevant variables tested in previous research (such as quality, prestige, or consumer identification) in order to understand which one(s) exert the strongest influence on brand trust.

  population. The results indicate that populations were similar in terms of age (z=1.52, p>.05) and education (z=.67, p>.05 for undergraduates and z=.95, p>.05 for graduates) but slightly different in terms of gender (z=2.76; p<.05). Thus, the profile of the post hoc study generally corresponds to that of the main study.The attitude scale's Cronbach's alpha (α = 0.981) is satisfactory, and an ANOVA was used to test the differences among brand attitude mean scores (63 participants x 4 brands = 252 responses), given that the assumptions for ANOVA were verified (no significant outliers, a (quasi) normal distribution, and homogeneity of variances). The ANOVA demonstrated no differences in mean scores (M McDonald′s = 4.28, 𝑆𝐷 = 1.85 𝑣𝑠 M KFC = 3.84, 𝑆𝐷 = 1.61 𝑣𝑠 M Subway = 4.50, 𝑆𝐷 = 1.67 𝑣𝑠 M Quick = 3.82, 𝑆𝐷 = 1.72; F statistic (3, 248) = 2.437; p = .065 > .05). In addition, post hoc comparisons between the highest and lowest level of brand attitude scores using the Tukey HSD test indicated that the mean attitude score for McDonald's did not significantly differ from KFC (sig. =

FigureFigure 2 :

 2 Figure 1: Research Model

  -

	Table 1 about here
	-

Table 3

 3 shows the coefficients validating the proposed model. First, the direct effects of the variables were analyzed. Brand globalness was positively related to brand affect (t=3.75, p<.001) and to brand innovativeness (t=2.34, p<.05), validating the direct effects of these variables. Consumers who perceive brands as more global feel more affect toward brands and perceive their greater innovativeness. The direct effects of brand affect on brand trust dimensions , i.e.; integrity (t=3.05,

p<.01),

benevolence (t=2.19, p<.05), and ability (t=6.73, p<.001)

were also validated. Similarly, results validate the direct effects of brand innovativeness on brand trust dimensions: integrity (t=3.46, p<.001), benevolence (t=5.75, p<.001), and ability (t=4.1, p<.001). Consumers who feel more affect

Table 1 : Demographic characteristics of the sample (N = 243)

 1

	Categories	N	%
	Age
	18-25	196	80%
	26-35	36	15%
	36-45	11	5%
	Gender
	Female	151	62%
	Male	92	38%
	Monthly Household Income
	<€1000	45	18%
	€1000-€2000	57	24%
	€2000-€4000	84	35%
	>€4000	57	23%
	Education
	High school	41	17%
	Undergraduate	92	37%
	Graduate	89	36%
	Doctorate	21	10%

Table 2 : Measurements

 2

	Constructs and items	Means (SD)	Stand. Loading	Composite Reliability	AVE	r2
	Brand Globalness			0.93	0.82	0.09

brand globalness and brand affect