اثر قیمت پایه بر رفتار جستجوگر مصرف کنندگان در یک سوپر مارکت : تجزیه و تحلیل موثر

The effects of product base price upon the duration of search behavior of consumers was investigated in a supermarket using an operant framework. Searching was interpreted as a pre-current behavior, influenced by the consequences for buying and consuming. Search duration was measured while consumers selected two cleaning products (Experiment 1) and two food products (Experiment 2), differing in base price. Search duration was significantly larger for the more expensive products. Consistent individual differences in search duration were also observed across products. These results, obtained from direct observation of search behavior, corroborate those found in the literature which used laboratory simulations and surveys, and illustrate the feasibility of an operant analysis of consumer behavior.

Consumers usually gather information before purchasing products. They may search for a favorable price among different stores or brands, examine product quality, try out new products or brands, or investigate payment conditions. This search may be brief and effortless, as when the person chooses a soft drink on a supermarket shelf, or long and costly, as when one is looking for an apartment. The identification of the variables that influence pre-purchase behavior may be important to our understanding of store and brand choice, sale promotion effectiveness, reactions to new products or packages, effects of store and product location, and such like. The amount of money that can be saved as search increases has been often cited as one of the variables that might influence search behavior. Some authors have suggested that perfectly rational consumers should continue to search until the expected gain from more search is less than its cost (Stigler, 1987). According to this analysis, consumers should know the distribution of prices in the market and the costs of searching, in order to maximize utility by balancing the amount of money saved from more search with the costs associated with that search. However, consumer behavior is not always optimal as described by traditional economic theory. It has been shown to be influenced by several other factors beyond the absolute amount of money saved and search costs (cf. Kahneman & Tversky, 1984; Thaler, 1985). Results stemming from experimental investigations, for instance, have shown that more participants said that they would make a trip to another store when they could get a discount of 33% than when the discount was equal to 4%, despite the fact that in both conditions they would save the same amount of money ($5) (cf. Tversky & Kahneman, 1981; Kahneman & Tversky, 1984). This inconsistency in their decisions may be explained, according to the authors (cf. Kahneman & Tversky, 1979), when one considers that financial transactions might be framed at different levels, namely, minimal, topical, or comprehensive. The minimal frame would consider only the absolute amount of money gained or lost, whereas a topical frame would be more inclusive, comparing, for example, the current price with the last price paid for the same product. A comprehensive frame would be even more inclusive and would consider, for instance, one’s monthly budget. In the case of the above mentioned results, participants would have been influenced by the percentage off the price, which would be a topical frame, rather than by the absolute amount of money saved, a minimal frame. Findings such as these led Kahneman and Tversky (1984) to conclude that sale prices are framed according to the percentage off rather than in terms of absolute amount of money saved. However, this conclusion has not been completely supported by subsequent research. Darke and Freedman (1993, Experiment 1), using a laboratory simulation, found that when the percentage to be saved by visiting another store was low (1% or 5%), the absolute amount of money ($5 or $25) to be saved influenced participants’ decision to extend price search. When the percentage of the base price to be saved varied more widely (5–25%), both variables influenced participants’ decisions (Darke & Freedman, 1993, Experiment 2). Another experiment corroborated and extended such results by showing that the percentage of discount influenced participants decision of ending price search for a product with low base price ($100) but not for a product with high base price ($300) (Darke, Freedman, & Chaiken, 1995). The authors explained these results by proposing a heuristic–systematic model of price search, which distinguishes between systematic and heuristic processing of information. Systematic processing would involve the examination of a large amount of information and would tend to be relatively effortful, whereas heuristic processing would involve simple decision rules and would require less effort. In the case of price search, a systematic processing would consist of visiting a large number of stores or examining a large number of brands in an attempt to find the best possible price. This type of search would occur when the consumer is highly motivated, as when a large amount of money can be saved (e.g., high base price, around $300). When the amount of money to be gained is small (e.g., because the base price is low), consumers would use the percentage discount of a sale price as a heuristic cue to decide to continue or stop searching. These different ways of cognitively processing information would, according to the authors, explain the results from their experiments and some apparently inconsistent results found in the literature (i.e., Blair & Landon, 1981; Della Bitta, Monroe, & McGinnis, 1981; Urbany, Bearden, & Weilbaker, 1988). Taken together, results from the above-cited experiments suggest that both percentage off the initial price and the amount of money that can be saved may influence consumer price search, depending upon the product base price and the size of the discount. Other investigations using data from surveys have also suggested the influence of product base price, or price variation, upon the behavior of searching for Christmas gifts (Laroche, Saad, Browne, Cleveland, & Kim, 2000) and price search in the retail grocery market (Urbany, Kalapurakal, & Dickson, 1996). All the investigations cited above illustrate the kind of theoretical explanation that has prevailed in the field for quite some time. In 1990, Foxall in his critique of the cognitive paradigm identified this tendency where he asserts that “the most widely-accepted and influential models of consumer behaviour derive from cognitive psychology which is rapidly assuming the status of a dominant, though not exclusive, paradigm for psychological research in general” (p. 8). Consumer choice, according to such models, is interpreted as a problem-solving activity, determined by rational and intellectual processing of information. Upon being presented with information concerning products, brands, prices and such like, consumers analyze, classify and interpret such information, transforming it, through more processing, into attitudes and intentions that ultimately produce choices and actual purchases (cf. Foxall, 1990, Foxall, 1997 and Foxall, 1998). This type of explanation has not been exempt from theoretical, conceptual and empirical criticism. Theoretically, one of the major critics of such theories was Skinner, 1953, Skinner, 1969, Skinner, 1977 and Skinner, 1985, who described them as incomplete, for they do not explain the presumed inner causes of behavior, fictional, for they are re-descriptions concealed as explanations, and unnecessary, for they could be replaced by much simpler environment-based theories (cf. Foxall, 1990). In the context of consumer behavior theory, such models have not emphasized the possible and probable effects of situational variables about which there is little systematic information (Foxall, 1997 and Foxall, 1998). Empirically, several assumptions of cognitive theories have not been supported by data from consumer behavior, since, as Foxall (1990) points out, consumers do not seem to be as rational, motivated and information-seeking as predicted by cognitive models. Moreover, a growing body of research has demonstrated that the prediction level of cognitive models of attitude is increased when they include situational variables, such as context specificity and previous behavior (cf. Foxall, 1997; Foxall, 2002b; Davies, Foxall, & Pallister, 2002). Independently of such criticisms, however, the present proposal can be justified as an attempt to extend the scope of consumer research beyond the prevailing cognitive paradigm. According to a relativistic perspective, the presentation of an antithetical theoretical position may, by itself, be salutary to the growth of the field (cf. Foxall, 1990, Foxall, 1998 and Foxall, 2002a; Foxall & Greenley, 1998). Based upon these assumptions, the present work presents an operant analysis of consumer search behavior and an empirical investigation of the effects of base price on the duration of search behavior in a supermarket.

The results obtained in Experiments 1 and 2 suggest that the duration of consumer search behavior per product unit is larger for products with higher base price. These findings were replicated across experiments despite several differences among target products. The two pairs of supermarket products investigated here belonged to different categories (i.e., cleaning products and food), had different numbers of alternative brands and package sizes (varying from 8 to 19), produced different search patterns (i.e., looking and smelling or just looking), occupied different space on the shelves (width equal to 4.20 or 7.00 m), and were displayed differently on the shelves (i.e., side by side, Experiment 2, or mixed, Experiment 1). Taken together, these results suggest that search duration per unit increases with product base price. This relation can be seen in Fig. 2, which shows mean search duration per product unit as a function of product base price for the data obtained in Experiments 1 and 2. Despite all the above-mentioned differences between the two pairs of products, Pearson correlation analysis indicates significant increases in search duration per product unit as a function of increases in product base price (r=0.34, N=70, p=0.004).These systematic results were obtained despite wide individual differences in search duration, indicated by the large values of standard deviations, proportionally to the means, found in both experiments. Results from Experiment 1 also suggest that such individual differences in search duration are consistent across products, that is, customers that spend more time searching for one product also tend to spend more time searching for other products. According to the interpretation proposed here, the probability and duration of searching would be a direct function of the potential increase in the probability of successful purchase (SDbuying) and an inverse function of search costs (S−cost). Assuming that, in each experiment, costs associated with searching were almost constant across products, the duration of searching would depend primarily upon the probability of successful purchase, which, in turn, would depend upon potential increases in product quality and potential decreases in price. Considering that prices for more expensive products usually vary more widely than those for cheaper ones, the probability of reinforcement for searching would be higher, based on larger possible savings, for products with higher base price. This increased probability of reinforcement for searching was expected to increase search duration. This effect, according to the present interpretation, would be dependent upon consumers’ experience with price variation in the market. When prices do not vary, for example, when paying government taxes or electric energy bills, search should be reduced. Moreover, if price variation for expensive products were equal, in terms of absolute amount of money, to those for cheap products, one would not predict more extended search for more expensive items. In such cases there would not be an increased reinforcement probability for searching for more expensive items. In the present experiments, means and standard deviations of product prices were highly positively correlated (r=0.99, N=4, p=0.008), which serves to illustrate the wider price variation for more expensive products so common in the market place. The present results corroborated the above predictions, for they suggest that both potential increases in product quality and potential decreases in price may influence search duration in a supermarket. The searching pattern of several customers observed in Experiment 1, characterized by smelling, indicates that search duration was influenced by potential increases in product quality. The larger search duration for products with higher base price, observed in both experiments, indicates that potential decreases in price also influenced search duration. However, as base price and price variation of the products investigated here were highly correlated, it would be necessary to test such predictions with products that have similar base prices and different price variations or different base prices and similar price variations. Results obtained here corroborate and expand data reported in previous studies using different methodologies. Evidence of extended pre-purchase search for products with higher base price can also be found in experimental investigations of price search in laboratory simulations (e.g., Darke & Freedman, 1993; Darke et al., 1995), in a survey based on questionnaire data about searching for Christmas gifts (Laroche et al., 2000), and in a survey, based on telephone interviews, about grocery shopping (Urbany et al., 1996). In these previous investigations, the main results were based on what individuals said they would do if they were really shopping or what they said they do when they go shopping. In both cases the results were based on what individuals say rather than on what they actually do. The present results suggest that consumers in fact extend search for more expensive items, although one would have to test if the same results are obtained for other types of search (e.g., searching for different stores or other kinds of products) and search measures (e.g., patterns instead of duration). The functional analysis advanced here may serve to illustrate the possibility of developing a coherent operant framework that explains and predicts consumer behavior, as defended by Foxall, 1990, Foxall, 1997, Foxall, 1998 and Foxall, 2002a and Foxall and Greenley (1998). This approach emphasizes the effects of situational variables rather than “intra-personal” factors as is usually the case with cognitively oriented theories (cf. Foxall, 1999). The results demonstrate systematic effects of base price on search duration despite the fact that they were obtained in a natural shopping environment, in which several variables remained uncontrolled. These orderly functional relations were observed independently of consumers’ awareness of their behavior, since no record of consumers’ verbal reports about their search patterns was obtained. Whether or not consumers are capable of accurately describing such differences in search duration of their own behavior is an empirical question that may be worth pursuing. The type of field study adopted here may be even used to investigate the level of correspondence between what consumers say about what they do and what they actually do. This kind of information has become particularly relevant in view of the fact that a great portion of research concerned with consumer behavior has been based on data from questionnaires and interviews, that is, on what consumers say about what they do. The present procedure may encourage the investigation of some aspects of what they actually do.