When Are Higher Social Class Consumers More and Less Brand Loyal Than Lower Social Class Consumers?: the Role of Mediating Variables

Rajesh Kanwar, San Diego State University
Notis Pagiavlas, San Diego State University
[ to cite ]:
Rajesh Kanwar and Notis Pagiavlas (1992) ,"When Are Higher Social Class Consumers More and Less Brand Loyal Than Lower Social Class Consumers?: the Role of Mediating Variables", in NA - Advances in Consumer Research Volume 19, eds. John F. Sherry, Jr. and Brian Sternthal, Provo, UT : Association for Consumer Research, Pages: 589-595.

Advances in Consumer Research Volume 19, 1992      Pages 589-595

WHEN ARE HIGHER SOCIAL CLASS CONSUMERS MORE AND LESS BRAND LOYAL THAN LOWER SOCIAL CLASS CONSUMERS?: THE ROLE OF MEDIATING VARIABLES

Rajesh Kanwar, San Diego State University

Notis Pagiavlas, San Diego State University

In this study we investigated the extent to which perceived risk mediates the influence of social class and purchase experience on brand loyalty. We found that the relationship between social class and brand loyalty is far more complex than previously thought. This study's results indicate that depending on the mediating variables and causal paths involved, brand loyalty can both increase and decrease with social class.

INTRODUCTION

Soon after Brown (1952) first published his findings on brand loyalty, researchers quickly identified its theoretical and managerial importance. Investigators realized that since brand loyalty (the repeated acquisition of a brand because of a distinct preference for it (Jacoby and Chestnut 1978)), or its absence, represented the final outcome of consumers' decision processes, it was seminal to understanding consumer behavior. And brand loyalty's managerial importance was indelibly established when researchers found that loyal customers account for most of a brand's sales (McConnell 1968).

Because brand loyalty is so central to consumer behavior and a brand's profitability, much research has been conducted on identifying the environmental (e.g., marketing) and individual factors that influence the amount or level of brand loyalty consumers develop towards brands. Thus, researchers have investigated the influence of individual factors such as social class (e.g., Carman 1970), demographic characteristics (e.g., Prasad 1975), personality (e.g., Carman 1970), prior experience (e.g., Tucker 1964), and perceived risk (e.g., Roselius 1971) on brand loyalty. In a similar vein, researchers have also examined the influence of environmental variables such as perceived product quality (McConnell 1968), price activity levels, and the number of brands available (Farley 1964), on consumer brand loyalty.

Of all these influences, one factor--perceived risk--seems to consistently influence brand loyalty across diverse products and consumer populations (e.g., Derbaix 1983; Sheth and Venkatesan 1968). Thus perceived risk has been found to influence brand loyalty or choice for disparate products and services such as drugs (Bearden and Mason 1978), consumer goods outlets (Prasad 1975), fabric softeners, laundry detergents, coffee, ice cream (Dunn, Murphy, and Skelly 1986), and automobiles (Peter and Ryan 1976). However, even more impressively, perceived risk has also been shown to influence brand loyalty across diverse consumer groups. For instance, despite the general paucity of cross cultural research (Albaum and Peterson 1984), perceived risk has been shown to influence brand loyalty in culturally and economically heterogeneous countries such as Mexico (Hoover, Green, and Saegert 1978), and India (Kanwar 1989), in addition to the U.S.

In fact, because perceived risk influences important consumer behaviors beyond brand loyalty, it has emerged as a significant aspect of consumer behavior in its own right. For instance, perceived risk has been shown to influence consumers' store choices (e.g., Potter and Coshall 1985), information search behaviors and information sources (e.g., Garner and Thompson 1986), new product adoption (e.g., Popielarz 1967), and involvement levels with products and decisions (e.g., Laurent and Kapferer 1985). Consequently, just like for brand loyalty, much research has been conducted on the factors that influence consumer risk perception levels. Thus substantial research has been conducted on exploring the influence of such individual and environmental factors as social class (Dash, Schiffman, and Berenson 1976), demographic characteristics (Schiffman 1972), personality (Schaninger 1976), product experience (McConnell 1968), and nature of the product (Dunn, Murphy and Skelly 1986), on risk perception. However, as prior discussion shows, many of the same factors have also been used in research on the factors that influence brand loyalty. For example, Schaninger (1976) and Carman (1970) investigated the influence of personality on perceived risk and brand loyalty respectively.

Thus, this extant research consists of three streams (i) the perceived risk-brand loyalty relationship, (ii) the influence of individual and environmental factors on brand loyalty, and (iii) the influence of individual and environmental factors on perceived risk. But, this research has ignored a related issue. To what extent does perceived risk mediate the influence of individual and environmental factors on brand loyalty? For example, we know that social class influences perceived risk as well as brand loyalty, and that perceived risk influences brand loyalty (e.g., Carman 1970; Chance and French 1972; Dash, Schiffman, and Berenson, 1976; Sheth and Venkatesan 1968). But, we do not know the extent to which perceived risk mediates the influence of social class on brand loyalty.

Thus, in general, in this study we are interested in determining the extent to which perceived risk mediates the influence of individual or environmental factors on brand loyalty. In specific, as Figure 1 shows, this study investigates the extent to which perceived risk mediates the influence of social class and purchase experience on brand loyalty.

We chose to investigate the affects of these two individual variables because of their theoretical and managerial importance. For instance, because social class and purchase experience influence a variety of important consumer behaviors (other than brand loyalty and perceived risk), such as shopping behavior, information search, store choice, and media exposure (see Rich and Jain 1968), they are among the most powerful methods of segmenting markets (e.g., Myers, Stanton, and Haug 1971; Schaninger 1981).

FIGURE 1

HYPOTHESIZED CAUSAL MODEL AND ASSOCIATED STRUCTURAL EQUATIONS

HYPOTHESES

As we discussed above, the purpose of this study is to explore the extent to which perceived risk mediates the influence of social class and purchase experience, on brand loyalty. As we mentioned before, brand loyalty increases with perceived risk (e.g., Roselius 1971; Sheth and Venkatesan 1968). That is, as perceived risk increases, consumers minimize or reduce the probability of, financial, social, or other losses by repurchasing products that they know perform satisfactorily. We could thus conclude that since the higher social classes perceive less risk (Dash, Schiffman, and Berenson 1976), they should also be less brand loyal than consumers who belong to the lower socioeconomic groups. But, research results do not support this conclusion. For example, Carman (1970) and Chance and French (1972) found that consumers from the higher social classes were more brand loyal than consumers from the lower social classes. We thus have seemingly contradictory findings.

In fact, some other research too suggests that consumers from the higher social classes should be less brand loyal than consumers from the lower social classes. As Bell (1964) and Hayes (1959) suggest, consumers from the higher social classes have a higher tolerance for risk (and may in fact seek out risk), than consumers from the lower social classes. Thus, because of their tolerance for risk, the higher social classes should be less brand loyal than consumers from the lower social classes. But, again, other research suggests that because the lower social classes are usually more concerned about preserving limited resources, they are more likely to switch brands than higher social class consumers (Dash, Schiffman, and Berenson, 1976). That is, because of a need to preserve resources, consumers from the lower social classes are less likely to be brand loyal than consumers from the higher social classes. Consequently, there seem to be competing and contradictory hypotheses regarding the relationship between social class and brand loyalty. However, as we discuss below, it may be possible to resolve this contradiction, by assuming that social class has several separate and contradictory influences on brand loyalty.

First, because measures of social class often include financial resources (see Ellis 1975), there is what we could call the direct affect of social class on brand loyalty (P14 in Figure 1). As we mentioned above, Dash, Schiffman, and Berenson (1976) suggested that consumers from the lower social classes are likely to switch brands when doing so helps them conserve resources. That is, social class should be positively related to brand loyalty. But, social class also has a second, indirect, affect on brand loyalty that is mediated by perceived risk.

As we mentioned earlier, people who belong to the higher social classes not only have a higher tolerance for risk (often seeking out risk), but because they are also more self-confident, they tend to perceive less risk than their counterparts from the lower social classes (Bell 1964; Hayes 1959; Prasad 1975). That is, if we consider the path:

social class -> perceived risk -> brand loyalty

in Figure 1, social class should be inversely related to perceived risk (i.e., a negative P34), while brand loyalty should of course increase with perceived risk (i.e., a positive P13). Thus, the net impact of social class on brand loyalty, through perceived risk, should be negative (P34 X P13), resulting in two related hypotheses regarding the affects of social class on brand loyalty. First:

H(1): In the causal diagram shown in Figure 1, when we consider the direct path between social class and brand loyalty, indicated by P14, brand loyalty should increase with social class (that is, P14 should be positive).

and second,

H(2): When we consider the causal path social class ¦ perceived risk ¦ brand loyalty in Figure 1, brand loyalty should decline with increases in social class (that is P34 X P13 should be negative), since perceived risk should decline as social class increases (a negative P34), while brand loyalty increases as perceived risk increases (a positive P13).

However, in addition to the above affects of social class, we are hypothesizing that social class has two other indirect affects on brand loyalty that are mediated by purchase experience. Research indicates that consumers who belong to the higher social classes not only consume a wider variety of products and services, than lower social class consumers (Myers, Stanton, and Haug 1971; Schaninger 1981), but that they use or buy these products more often too (Hirisch and Peters 1974). Consequently, people who belong to the higher social classes are much more experienced as consumers than people from the lower social classes. Because of this greater breadth and depth of purchase experience, the higher class consumers should posses highly developed consumer and decision-making skills that enable them to make consumption decisions, and evaluate products and marketing communications, with confidence and relatively little risk. They should, therefore, both perceive less risk, and also be more willing to switch brands, than consumers from the lower social classes. In other words, both perceived risk and brand loyalty should decrease with experience. However, since purchase experience increases with social class, we are hypothesizing that when we consider the two paths:

social class -> purchase experience -> perceived risk -> brand loyalty

and,

social class -> purchase experience -> brand loyalty

in Figure 1, brand loyalty should decline as social class increases because:

H(3): As purchase experience increases, both the amount of perceived risk and brand loyalty should decline (negative P23 and P12). Thus, the overall impact of social class on brand loyalty along the two paths should also be negative (both "P24 X P12" and "P24 X P23 X P13" should be negative), since purchase experience increases with social class, and brand loyalty increases with perceived risk (both P24 and P13 are positive).

METHODOLOGY

In order to test our hypotheses, we conducted a study with Asian Indian women. As we briefly indicated earlier, most consumer behavior studies have been conducted with U.S. consumers (Albaum and Peterson 1984). Consequently there is a great need for cross-cultural research that replicates and extends the results of studies conducted with U.S. consumers, to other cultures and economies. Conducting this study with women from India makes just such a contribution. But, such a strategy carries the risk that the study's results may be culturally driven. Although possible, we feel that such concerns are at least somewhat ameliorated by a variety of factors. First, as mentioned earlier, prior research found that perceived risk produces similar consumption behaviors across diverse cultures and economies, including India (Hoover, Green, and Saegert 1978; Kanwar 1989), somewhat alleviating the concern that this study's results may be culturally driven. In addition, as Figure 1 shows, our causal model includes, indeed builds on and extends, some previously established relationships (e.g., the perceived risk-brand loyalty relationship). Thus, we can test whether our study replicates these established relationships. If it does, we would have added confidence that this study's results are not culturally driven. And, we would have also made an incremental contribution towards establishing the cross-cultural validity of prior findings related to perceived risk, and meeting the need for more cross-cultural research.

Sample

Altogether 222 women, residing in a major city in Southern India were used as subjects in this study. A two-stage sampling plan was used to select these women. In order to recruit women from the middle and upper social classes, we randomly selected three residential areas where middle and upper middle class families were known to reside in the city of interest. Then residential maps of these three areas were used to randomly select 150 single family homes for participation in the study. One of three women investigators then visited each home, and administered the questionnaire used in the study to the "lady of the house." If the "lady of the house" was not available, up to two call backs were made to contact the selected respondent. Because of the high call back rate, the non-response rate was only 4%, resulting in the final sample of 144 women from these areas.

Exactly the same procedure was used to recruit women belonging to the lower social classes, except that these women were recruited from two randomly chosen lower social class residential areas. Although we had randomly chosen ninety single family homes, from these areas for participation in the study, only seventy-eight of these women participated in this study because of the slightly higher refusal rate in these areas.

Respondent Characteristics

The average middle and upper social class woman was married (98%), 36 years old, and had two children. Ninety-six percent had completed high school, and 81% had undergraduate or higher degrees (in comparison the country's literacy rate is 36%). However, only 11% of the women worked outside the home, 89% classifying themselves as housewives. The average family income was about $2400 per year, as compared to the national average household income of about $1200. Thus, as desired, the women in the sample belonged to India's middle and higher social classes, with higher than average education and incomes.

In contrast the average woman from the lower social classes was 35 years old, married, and had 2.4 children. Not only did a much lower proportion have undergraduate degrees, but the average family income of $1250 was almost half that of the higher social classes. Less than 10% worked outside the home, more than 90% classifying themselves as housewives.

Procedures

Each subject answered an interviewer administered questionnaire designed to measure demographic characteristics and perceived risk for twenty non-durable consumer product categories such as personal care products (e.g., hair removers), over-the-counter drugs (e.g., headache remedies), and household and food products (e.g., detergents and instant coffee).

Perceived risk for these product categories was measured with scales similar to those used by other researchers (e.g., Dean, Engel, and Talarzyk 1972). Two five-point scales were used. Although four-point scales have been more commonly used to measure perceived risk (e.g., Dean, Engel, and Talarzyk 1972; Hoover, Green, and Saegert 1978), five-point scales were used in this study because pretests indicated that these were more suitable, than the four-point scales, for Indian consumers. The first scale measured the degree of perceived similarity between brands in each product category (1 = very similar, 5 = not at all similar). The second scale measured the amount of risk the consumer associated with trying new products in each product category (1 = no chance at all, 5 = very high chance). The scores on the two scales were then summed to produce the amount of risk each subject perceived for each product category. In addition, we used a similar five point scale to measure brand loyalty towards each product category, requesting consumers to estimate the likelihood that they would try brands that they had not tried before. Since subjects only responded to the perceived risk and brand loyalty scales for the products that they used, we then constructed mean indices of perceived risk and brand loyalty for each subject by averaging across these scales for the products respondents used.

We also computed an index of social class for each respondent by summing the scores on two four point scales measuring each housewives level of education, and the family's income. Although previous research has generally included occupation with income and education to produce indices of social class (Ellis 1975), we did not include occupation in our index because our sample consisted of women, who usually do not work outside the home in India (as shown by the high percentage of the women in the sample who considered themselves housewives).

Finally, we counted the number of different products each woman used, and used this count as an indicant of the breadth of each consumers' purchase experience.

RESULTS

As discussed earlier, we had hypothesized that the direct influence of social class on brand loyalty would be positive, but that the indirect affect, mediated by perceived risk, would be negative. That is, P14 would be significant and positive, but that P34 would be negative while P13 was positive, so that the overall impact of social class on brand loyalty would be negative (P34 X P13). We had also hypothesized that while consumers purchase experience would increase with social class (a positive P34), consumers perceived risk and brand loyalty would decrease with increasing purchase experience (negative P23 and P12), so that the overall influence of social class on brand loyalty, that was mediated by perceived risk and purchase experience, would be negative.

FIGURE 2

SOLUTIONS OF THE STRUCTURAL EQUATIONS AND CAUSAL MODEL SHOWN IN FIGURE 1

We tested these hypotheses by using regression analyses to solve the structural equations shown in Figure 1. Figure 2 presents the results we obtained when we solved these equations.

We had earlier expressed our concern that because this study was conducted with Asian Indian women, its results could be culturally driven. As we had then mentioned, such concerns would be somewhat reduced if our study replicated previously established findings. As Figure 2 shows, our study clearly does so.

First, like previous researchers (Hirisch and Peters 1974; Myers, Stanton, and Haug 1971; Schaninger 1981) we too found that consumer purchase experience increased with social class (P24 = .38, p < .01). That is, just like in the U.S., Indian consumers who belong to the higher social classes consume a wider variety of products, than consumers from the lower social classes. Similarly, as expected, we also found that perceived risk was positively related to brand loyalty (P13 = .36, p < .01). That is, just like U.S. consumers, Indian consumers too use brand loyalty as a method of reducing risk. Thus, since our study replicates both these established relationships, we can be at least somewhat confident that the results and test of hypotheses we report below, are not culturally bound.

As figure 2 shows, our hypotheses were only partially supported. Contrary to expectations, social class only influences perceived risk indirectly. When purchase experience is included in the causal model, social class does not directly influence perceived risk (P34 = 0). However, we did find that social class had a significant affect on perceived risk, that is mediated by purchase experience (P24 X P23). Although contrary to expectations, this relationship was positive rather than negative, that is perceived risk increased with social class, it does suggest that prior research (e.g., Dash, Schiffman, and Berenson 1976), may have overlooked the mechanisms thorough which social class influences risk perception.

Second, and perhaps more important, we found that social class had both positive and negative influences on brand loyalty. For example, we found that as expected, people who are highly experienced consumers are less likely to be brand loyal than consumers with lower levels of purchase experience (P12 = -.18, p < .01). Consequently, since purchase experience increases with social class, the overall affect of social class on brand loyalty is negative (P24 X -P12). That is, when one considers the causal path:

social class -> purchase experience -> brand loyalty

brand loyalty decreases as social class increases. People from the lower social class are likely to be more brand loyal than people from the higher social classes. Similarly, although only marginally significant (P14 = -.13, p < .10) it also seems that when no mediating variables are involved, brand loyalty decreases as social class increases. Perhaps factors such as higher education act to reduce brand loyalty. Because well-read or educated consumers are less likely to be influenced by marketing communications (Levy 1966), consumers from the higher social classes may perceive fewer differences between brands, and are thus more willing to switch brands than lower class consumers.

However, if we consider the causal path:

social class -> purchase experience -> perceived risk -> brand loyalty

it seems that brand loyalty increases with social class, since the sequential relationships between these variables are all positive (P24, P23, P13, are all positive). Thus it seems that depending on the causal path or intervening variables involved, like we had expected, social class had both negative and positive influences on brand loyalty.

Finally, we should also mention here that our finding that perceived risk increases with purchase experience was contrary to expectations. Perhaps, as purchase and product experience increase, consumers perceive greater and greater differences between brands and products, increasing their level of perceived risk. However, only future studies can test the validity of this explanation, since our study does not have the data to allow such a test.

CONCLUSION

Our findings indicate that the influence of social class on brand loyalty is far more complex than previously thought, perhaps explaining the often inconsistent results of previous studies. For instance, as we had discussed earlier, some studies have indicated that perceived risk decreases as social class increases (Dash, Schiffman, and Berenson 1976). Since brand loyalty is high when perceived risk is high, these results suggest that consumers from the higher social classes should be less brand loyal than consumers belonging to the lower social classes. But, studies that directly investigated the relationship between social class and brand loyalty did not support this conclusion. For example, Carman (1970) and Chance and French (1972) found that brand loyalty increased with social class. Our results seem to explain these inconsistent findings. The relationship between social class and brand loyalty is far more complex than previously thought. Because of intervening or mediating variable such as purchase experience, and perceived risk, both positive and negative relationships between the two variables are possible.

This study's results also indicate that current understanding of the relationship between social class and perceived risk may be oversimplified. The relationship between these two variables seems to be entirely explained by intervening variables such as purchase experience. When this variable is considered, the direct relationship between social class and perceived risk simply disappears.

However, in addition to uncovering the complexity of the relationship between social class and brand loyalty, this study also made another important contribution. By conducting this study with women from India, we not only provided further evidence on the cross-cultural validity of previous research on social class, perceived risk, and brand loyalty, but we also extended this research. Thus, the study made an incremental contribution toward fulfilling the great need for cross-cultural research that validates and extends the findings that have emerged with U.S. consumers.

REFERENCES

Albaum, Gerald, and Peterson, Robert, A. (1984), "Empirical Research in International Marketing: 1976-1982," Journal of International Business Studies, Spring/Summer, 161-173.

Bearden, William, O., and Mason, Barry, J. (1978), "Consumer-Perceived Risk and Attitudes Toward Generically Prescribed Drugs," Journal of Applied Psychology, 63(6), 741-746.

Bell, William, E. (1964), "Consumer Innovators: A Market for Newness," Proceedings, Winter Conference, American Marketing Association, 85-93.

Brown, George, H. (1952), "Brand Loyalty--Fact or Fiction?," Advertising Age, 23, June 9, 53-55.

Carman, James M. (1970), "Correlates of Brand Loyalty: Some Positive Results," Journal of Marketing Research, 7, February, 67-76.

Chance, William, A., and French, Norman, D. (1972), "An Exploratory Investigation of Brand Switching," Journal of Marketing Research, May, 226-229.

Dash, J.R., Schiffman, L.G., and Berenson, C. (1976), "Risk-and Personality-Related Dimensions of Store Choice," Journal of Marketing, January, 32-39.

Dean, M. L., J. F. Engel, and W. W. Talarzyk (1972), "The Influence of Package Copy Claims on Consumer Product Evaluations," Journal of Marketing, 36, April, 34-39.

Derbaix, C. (1983), "Perceived Risk and Risk Relievers: An Empirical Investigation," Journal of Economic Psychology, March, 3(1), 19-38.

Dunn, Mark, G., Murphy, Patrick E., and Skelly, Gerald, U. (1986), "Research Note: The Influence of Perceived Risk on Brand Preference for Supermarket Products," Journal of Retailing, 2, Summer, 204-216.

Ellis, Richard, B. (1975),"Composite Population Descriptors: The Socio-Economic/Life Cycle Grid," in Mary Jane Schlinger ed., Advances in Consumer Research, 2, Ann Arbor, Mich: Association for Consumer Research, 485-486.

Farley, John, U. (1964), "Why Does "Brand Loyalty" Vary Over Time," Journal of Marketing Research, November, 9-14.

Garner, S.J., and Thompson, Howard, A. (1986),"Patient Perceived Risk in the Purchase of Physician Services," Journal of Professional Services Marketing, 1, Fall/Winter, 149-159.

Hayes, Samuel, P. (1959), "The Adoption of New Products: Process and Influence," Foundation For Research on Human Behavior, Ann Arbor: University of Michigan Press.

Hirisch, R., and Peters, M. (1974), "Selecting the Superior Segmentation Correlate," Journal of Marketing, 38, 60-63.

Hoover, Robert, J., Green, Robert, T., and Saegert, Joel (1978), "A Cross-National Study of Perceived Risk," Journal of Marketing, July, 102-108.

Jacoby, Jacob and Chestnut, Robert (1978), Brand Loyalty Measurement and Management, New York, N.Y.: John Wiley and Sons.

Kanwar, R. (1989), "Perceived Risk and Brand Loyalty in The Indian Consumer," paper presented at the IAMM 1989 Annual International Conference.

Laurent, Giles, and Kapferer, Jean-Noel (1985), "Measuring Consumer Involvement Profiles," Journal of Marketing Research, February, 22, 41-53.

Levy S.J. (1966), "Social Class and Consumer Behavior," in On Knowing the Consumer, J.W. Newman ed., New York, N.Y.: John Wiley and Sons.

McConnell, Douglas, J. (1968), "The Development of Brand Loyalty: An experimental Study," Journal of Marketing Research, 5, February, 13-19.

Myers, John, H., Stanton, Roger, R., and Haug, Arne, F. (1971), "Correlates of Buying Behavior: Social Class vs. Income," Journal of Marketing, 35, October, 8-15.

Peter, Paul, J., and Ryan, Michael, J. (1976), "An Investigation of Perceived Risk at the Brand Level," Journal of Marketing Research, 13, May, 184-188.

Popielarz, Donald, T. (1967), "An Exploration of Perceived Risk and Willingness to Try New Products," Journal of Marketing Research, 4, November, 368-372.

Potter, Robert, B., and Coshall, John, T. (1985), "The Influence of Personality-Related Variables on Microspatial Consumer Research," Journal of Social Psychology, 125(6), Dec., 695-701.

Prasad, Kanti, V. (1975), "Socioeconomic Product Risk and Patronage Preferences of Retail Shoppers," Journal of Marketing, 39, July, 42-47.

Rich, Stuart, U., and Jain, Subhash, C. (1968), "Social Class and Life Cycle as Predictors of Shopping Behavior," Journal of Marketing Research, 5, February, 41-49.

Roselius, Ted (1971), "Consumer Rankings of Risk Reduction Methods," Journal of Marketing, 35, 56-61.

Schaninger, Charles, M. (1976), "Perceived Risk and Personality," Journal of Consumer Research, 3, September, 95-100.

Schaninger, Charles M. (1981), "Social Class Versus Income Revisited: An empirical Investigation," Journal of Marketing Research, May, 192-208.

Schiffman, Leon, G. (1972), "Perceived Risk in New Product Trial by Elderly Consumers," Journal of Marketing Research, 9, February, 106-108.

Sheth, Jagdish and Venkatesan M. (1968), "Risk-Reduction Processes in Repetitive Consumer Behavior," Journal of Marketing Research, 3, 307-311.

Tucker, W.T. (1964), "The Development of Brand Loyalty," Journal of Marketing Research, August, 32-35.

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