Consumer Behavior Research

This article analyzes 12 years of recent scholarly research on consumer behavior published in the five leading international journals in this field. Analyzing academic contributions to a specific area of research provides valuable insights into how it has evolved over a defined period. The approach was to briefly discuss content analysis and its application in scholarly literature review studies. The methodology used here involves the classification of topics to evaluate key trends in consumer behavior literature. It includes a ranking of topics published, typology of the published articles, the research classification in terms of methodologies, and analysis techniques. The most cited articles in the field and within each journal are also examined. The comprehensive literature review of consumer behavior research undertaken in this article could advance the discipline of consumer behavior research by elucidating the evolution of consumer behavior literature in the studied period.


Introduction
Consumer behavior has always been an area of major interest for social science researchers, witnessing an explosion over the past 50 years (MacInnis & Folkes, 2010). Accordingly, literature on this topic has been the center of attention in a number of previous studies (Arndt, 1986;Battalio et al., 1974;Belk et al., 2012;Hameed, Waqas, Aslam, Bilal, & Umair, 2014;Hawkins & Mothersbaugh, 2009;Howard & Sheth, 1968;Robertson & Kassarjian, 1991;Solomon, 2013). Literature on consumer behavior is diverse and extensive as changes in society, economics, and technology affect the way consumers behave.
Inevitably, these changes lead to changed consumer behavior studies by which, when, how, and why the topics are studied. Like any other discipline, systematic analysis of the knowledge development status of consumer behavior field is critical in ensuring its future growth (Williams & Plouffe, 2007). It is of a greater importance for a field of research such as consumer behavior that, as MacInnis and Folkes (2010) claimed, is thriving by the growing number of articles and topics examined. One way of conducting this systematic analysis is through studying scholarly literature, which can illustrate a discipline's intellectual history (Pasadeos, Phelps, & Kim, 1998). In this regard, to assess a discipline's accrued knowledge, in-depth reviews of research published in peer-reviewed journals are the most relevant and useful resources (Üsdiken & Pasadeos, 1995;Williams & Plouffe, 2007). The importance of consumer behavior in the different disciplines of business literature also suggests the need for an up-to-date look at the literature in this field. Beyond helping consumer behavior scholars and practitioners develop a better understanding of the direction in which the field is progressing and identify the gaps, such studies will provide a guideline for them in positioning their future research and marketing efforts.
In this regard, a technique such content analysis, which can be used to analyze message content and handling, is ideal for conducting such literature review studies. As an observational research method, content analysis systematically evaluates the symbolic content of all forms of recorded communications (Sattari, 2012). It can be considered as an empirical starting point generating new research evidence about the nature and effect of specific communications (Kolbe & Burnett, 1991;Vallet-Bellmunt, Martínez-Fernández, & Capó-Vicedo, 2011). Content analysis not only helps identify central issues to the field but can also help to reveal areas where more work needs to be undertaken, particularly if these are considered to be important and defining issues in the discipline (Cokley, Caldwell, Miller, & Muhammad, 2001). Such integrative review of consumer 645638S GOXXX10.1177/2158244016645638SAGE OpenPeighambari et al.

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1 Linnaeus University, Vaxjo, Sweden 2 Luleå University of Technology, Sweden behavior research as a diverse discipline with an overwhelming scope in peer-reviewed journals is necessary if the field is to progress in a systematic fashion. Moreover, although content analysis of journals can be time-consuming and data intensive, such studies provide direction into future areas of needed inquiry in the field by offering insight about the topical, methodological, and theoretical trends into research communities (Williams & Plouffe, 2007).
According to Buboltz, Miller, and Williams (1999), an examination of articles published in a journal reveals the trends and issues that impact the discipline. A content analysis of journal articles within a specific discipline allows for an examination of the kinds of topics that are deemed important to the particular field the journal represents (Cokley et al., 2001). In consumer studies, marketing research, and other business disciplines, literature investigations can also provide insights into the specific journals' contributions to the field as well as the specific published works (Sattari, 2012). This, in turn, can be used to describe a discipline's intellectual history (Pasadeos et al., 1998). A comprehensive content analysis of peerreviewed journal publications in a field encourages the scholars to assess the entire "forest" of knowledge by taking a step back from their individual "trees" (Williams & Plouffe, 2007).
Such studies have been conducted within a variety of disciplines based on publications in the most respected journals. Two examples are the Pasadeos et al. (1998) and West (2007) studies reporting on the impact of advertising on researchers during different periods of time. Buboltz et al. (1999) and Cokley et al. (2001) have contributed similar studies in psychology. Others have targeted the consumer behavior field such as the studies done by Kassarjian (1977) and Helgeson, Kluge, Mager, and Taylor (1984), but there is no current review of the field. Therefore, given the importance of consumer behavior research, a comprehensive literature study of more recent contributions to this area of research is warranted.
In this regard, this article serves to assess the structure and evolution of consumer behavior research content in business disciplines. The purpose of this literature review is to systematically review consumer behavior research over a 12-year period in five major journals in the field. Such an examination of diverse research in this discipline allows for identification of shifts and changes in a longitudinal manner. This article presents the results of a comprehensive content analysis covering 12 years of research in the domain of consumer behavior. Our review, which evaluated more than 1,000 articles published across five key journals, provides a descriptive snapshot of the status of consumer behavior research including the most dominant topics based on Helgeson et al.'s (1984) framework and methodological and analytical approaches, in addition to citation statistics of the reviewed consumer behavior articles.

Method
To examine the content of consumer behavior literature, trace its evolution, and identify the main streams of research over time, a content analysis was first performed on the articles focusing on consumer behavior. Helgeson et al. (1984) classified 32 years of consumer behavior literature from selected journals and proceedings. As there did not seem to be a comprehensive review and classification of consumer behavior topics in the literature, they tried to rectify the situation by examining the evolution of consumer behavior literature as a topic between 1950 and 1981. No similar research has been carried out since 1981, so this study replicates Helgeson et al.'s work based on the framework proposed by Berthon, Pitt, Ewing, and Carr (2002) by extending its context to the period 1998-2009.
The purpose of this article is, therefore, to cover 12 years (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)) of literature to investigate consumer behavior growth as a research topic in the literature. Like Helgeson et al. (1984), our objective is not to evaluate the results of the research but to categorize and evaluate trends as found in the following publications: The choice of these five journals is straightforward as they have held positions as the top consumer behavior journals and business journals for decades. Evidence of this comes from many sources, such as the ABS' (Chartered Association of Business Schools) Academic Journal Quality Guide Studies evaluating these journals at the top level of business journals.
Evidence is also available from the Web of Science Internet library source and Thomson Reuters journal citation reports, both measuring the influence of publications based on impact factors (defined as the frequency with which articles from a journal have been cited). The last journal citation report from Web of Science (2014) shows that JCR (5-year impact factor of 5), JM (5-year impact factor of 7.42), JMR (5-year impact factor of 3.77), JA (5-year impact factor of 1.73), and JAR (5-year impact factor of 2.54) have consistently been positioned as top influential business journals (Journal Citation Reports, 2014). Moreover, the idea behind choosing these journals was to cover various disciplines among business studies such as marketing, advertising, and consumer research. Choosing these five journals also helped to evaluate articles published by different publishers, namely, the American Marketing Association (AMA), Oxford University Press, Taylor & Francis, and World Advertising Research Center.
Moreover, as claimed by Furrer, Thomas, and Goussevskaia (2008), established influential journals, such as the ones chosen in this study, set the bar for studies within their frame of reference by forming the theoretical and empirical work in their discipline.
However, it must be said that notable contributions to consumer behavior research have come from other sources, particularly books and monographs, which we did not examine. In total, 2,915 articles published in the five journals during the period under study were included in our review.
The first decision made by each reviewer was whether the article dealt with consumer behavior. Hence, in the initial phase of this research, the authors manually reviewed every issue of the five examined journals to identify articles for inclusion in the analysis. First each article's title, abstract, and keywords were evaluated, and if they included consumer behavior (or behaviour), then the article would be on the list for further analysis. In many cases, this criterion was not met so the full article was inspected and skimmed through to determine whether that the article was related to consumer behavior. A very small number of publication entries, such as editorials, points of view, abstracts, and book reviews, were excluded from the analysis. In total, this identification phase yielded a sample of 1,263 consumer behavior articles (Table 1).
The second phase of the study involved systematically categorizing the major aspects of each chosen article. Both deductive and inductive procedures were conducted to determine the categories used in the content analysis of the articles. The initial inclusion of content topics relied on deductive procedures, meaning that the reviewed consumer behavior articles were classified into 37 topics, which were divided into four major areas, Internal, Purchase Process, External, and Miscellaneous (Table 1), as previously determined by Helgeson et al. (1984). This categorization can be explained through Wright's (2006) perspective in that the variety of human internal factors, external environment, and problemsolving processes should be identified when trying to understand consumer behavior. Accordingly, the Internal category covers topics associated with consumers' individual and psychological factors, whereas the topics categorized under External involve situational and social factors.
To ensure consistent classification of multitopic articles, in cases where an article could be classified under more than one topic, the authors discussed the article and obtained a consensus about the closest topic, which the article covered. Then, each article was classified based on its research typology as being either qualitative, quantitative, or both. In the next step, by using Google Scholar, the number of citations for each selected article was gathered.
Articles were further categorized according to research methodology. Helgeson et al. (1984) used a group of four methods: Survey, Experiment, Discussion, and Other. Inductive procedures were used to develop additional categories for the articles' methodologies and analysis techniques. This was done by each author independently reviewing the contents of articles they were assigned and then meeting and

Analysis and Results
The number of consumer behavior articles during the studied time period ranged from 66 per year in 1998 to 156 per year in 2009 (Table 1). These numbers as a percentage of total articles appearing in the literature in the five selected journals are illustrated in Figure 1. At least three characteristic life-cycle patterns seemed to emerge, when plotting the percentage of consumer behavior articles devoted to each of four major areas over time ( Figure  2). The first pattern is exemplified by External area, which, despite its consistent appearance in the literature, showed a decline in the number of articles compared with the other three areas. This pattern for External topics is negatively skewed with periodic peaks through time. A second pattern is exhibited by Internal topics, which are still in a growth stage showing a gradually increasing interest in the literature. The skewness for pattern is positive without any significant periodic peaks through time. The Purchase Process area revealed a third pattern, which is also positively skewed but with some periodic and major peaks through time. Despite a decline in the height of these peaks over time, the Purchase Process topics remain an important part of the literature, and this trend is growing. Table 2 exemplifies the frequency and percentage of articles that each of the main area of topics covered compared with the reviewed articles in consumer behavior fields in the reviewed journals.
As mentioned above, 37 major topics in consumer behavior were selected in categorizing articles, which were then grouped into four major areas. Using these categories, Table  3 shows the percentage of occurrence of each topic within the reviewed consumer behavior articles.
According to the findings, the most studied topic within consumer behavior articles in the five journals was Perception, which was covered in 12% of the articles. Only slightly less common, Attitudes came next (11.5%), while the third topic, at almost half the size of the preceding two, with 6.2%, was Brand awareness/loyalty.
In Table 3, bold fonts highlight the most studied topic in each major area. As discussed earlier, the present study classified articles based on their research typology, methodology, and the data analysis techniques used. Findings revealed that a large number of the reviewed consumer behavior articles were classified as quantitative studies (76%), as shown in Table 4. To dig deeper into this matter, we also evaluated the relationship between the types of studies (qualitative and quantitative) with respect to the four topic categories as shown in Table 5.
Moreover, according to the research methodology, experiments and surveys were the most common instruments for conducting consumer behavior research. This can be described as the nature of consumer behavior as related to studying and observing consumers. The articles were also  classified by using one of the previously mentioned 10 analytical techniques. Table 6 presents the frequency and percentage of each research methodology and the analysis techniques used in the reviewed articles.
Moreover, Table 7 shows the trends regarding analytical techniques used during the 12 years studied as the percentage of all consumer behavior articles in each year.
In comparison with the study done by Helgeson et al. in 1984, there has been tremendous growth in the use of complex statistical techniques such as SEM. This may be due to the fact that these techniques involve advanced computer software and packages that did not exist in 1984. It may also be the result of an increase in the number of consumer behavior articles that conducted scientific hypothesis testing generated from a theory base. The complexity of the articles written has also witnessed an increase due to growing emphasis on theoretical foundations and multivariate statistics, linked to advances in computer manipulation of data. Thus, to comprehend the more recent consumer behavior articles, readers are required to have a greater knowledge of the theoretical roots of articles and more statistical sophistication than had been necessary for earlier articles.
Another consequence of the data analysis concerns articles that have been cited the most often in consumer behavior literature. Table 8 shows the 15 most cited articles in all journals, whereas Table 9 illustrates the three most influential articles from each journal.

Conclusion
The results presented in this article suggest many implications for the consumer behavior research community, researchers, journal editors, and reviewers, as well as for the practitioners. In this regard, this article not only serves to evaluate the structure and evolution of the literature in consumer behavior field but also presents some assumptions about further developments in this literature.
By helping consumer behavior scholars to better understand the direction in which the field is going, the article is intended to provide a guideline for scholars in positioning their future research efforts. The results of this article provide consumer behavior researchers with a concrete perspective on what has been published on the subject area by indicating hot topics, research methods, and analysis techniques. The findings of this study highlight the most important consumer behavior topics and the most influential articles in the field based on citation frequency. The number of topics studied in consumer behavior showed a dramatic growth and revealed some general patterns during the 12 years studied in this article. According to the results, authors aiming to have an article published in a journal will have a better understanding of the different trends consumer behavior research has had during the studied period. Moreover, potential authors, researchers, and interested readers may use the information presented as a means to assess the field.
The findings of this research also provide journal editors and reviewers with a wider (global, in a sense) perspective regarding the publication trends and themes on consumer behavior research topics, methods, and statistical analysis.
Practitioners can use this study to indicate which journals to consult as sources of information on specific topics. The analysis of the topic areas among the reviewed articles provides evidence that certain topic areas (Purchase Process and Internal) enjoyed consistent popularity among the chosen journals' editors and reviewers during the studied years, while the interest in topics related to external aspects of consumer behavior has decreased among the five journals. This is in line with the ever-changing environment of consumers' decision making and the move from profit-focused perspective of companies to a relationship-focused one to increase loyalty. This seems to be in line with the evolution of consumers' preferences too, meaning that scholarly work in these journals has recognized this change and has begun to investigate these changes in consumer behavior.

Limitations and Avenues for Future Research
While the content analysis conducted in this study provides useful information to consumer behavior researchers and practitioners, several limitations of the study must be indicated. First, the five journals analyzed here do not represent the entire body of consumer behavior research. In this regard, future studies could select a larger number of journals, as well as conference proceedings and books from various disciplines. Furthermore, this article reviewed consumer behavior studies published in a specific period. Extending this time frame would, of course, strengthen the results and their generalizability. Moreover, as Yale and Gilly (1988) argued, any content analysis may, to some extent, have a learning bias, meaning that when the judges (in our case the authors of the article) review more articles, they become more skillful and intuitive, which may result in a different manner of inspection for the articles evaluated earlier versus the ones assessed later in the process. As the reviews of the articles done in this study are based on the judgments of its authors, further research may come up with new and slightly different results. Therefore, a more systematic and transparent coding scheme is recommended for future study.
Future studies of the consumer behavior research literature can also investigate authorship of the articles, including which authors have had what impact on the discipline and which scholars from which institutions have been productive in terms of consumer behavior publications. Finally, future research can investigate and categorize the results and the implications of articles in each topic, as well as the theories that have been used or applied in those studies.

Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding
The author(s) received no financial support for the research and/or authorship of this article.