Determinants of Sustainable Food Consumption: A Meta-Analysis Using a Traditional and a Structura Equation Modelling Approach
International Journal of Psychological Studies
Based on a database of 16 empirical studies, this MASEM study aims to provide an overview of existing antecedents of sustainable food consumption within an integrative framework based on the TPB. Among the antecedents, Personal Norm, Attitude and Subjective Norm displayed strongest effects on Intention, followed by Beliefs, Perceived Behavioral Control and Ethical Concern, which were also within the scope of medium to large. As for the correlations of Behavior, Personal Norm, Attitude and
... Attitude and Subjective Norm showed strongest effects, and the effects of Intention, Beliefs and Perceived Behavioral Control were also within the scope of medium to large. Results of the MASEM study indicate that both TPB and extended TPB models have statistically acceptable power in explaining the intention and behavior of sustainable food consumption, while a slight increase was made to the amount of explained variance of intention by adding Personal Norm to TPB. The results of our meta-analyses give readers an understanding of the magnitude and significance of relationships between antecedents and intention in the sustainable food consumption domain. The TPB, which deals with the information processing of the individual whose behavior is guided by rational decisions, is perhaps the most influential theory for predicting and explaining human behaviors (Armitage & Conner, 2001). According to the TPB, the strongest and most proximal predictor of volitional behavior is one's behavioral intention, which is an indication of a person's readiness to perform a given behavior. As a general rule, the stronger the intention to engage in behavior, the more likely should be its implementation. The TPB further postulates three main factors which determine one's behavioral intention: attitude toward a behavior (AB), subjective norm (SN) and perceived behavioral control (PBC), with each predictor weighted for its importance in relation to the behavior and the population of interest. Attitude toward a behavior reflects the degree to which performance of the behavior is positively or negatively valued. Subjective norm is the perceived social pressure to engage or not to engage in a behavior. Perceived behavioral control refers to people's perceptions of their ability to perform a given behavior. According to the TPB, the more positive one's attitude and subjective norm, and the greater one's perceived behavioral control regarding a behavior, the more likely a person is to intend to perform that behavior. The latter construct, PBC, is not only a direct antecedent of intention as are attitudes and subjective norms, but also a determinant of behavior along intention in cases where performance of the behavior is less volitional. In practice, intention and PBC are often found to have main effects on behavior, but no significant interaction. Several meta-analytic reviews support the success of the TPB in the prediction of behavior and attitude-behavior consistency for a wide range of human behaviors (e.g.These meta-analyses have reported a considerable attitude-intention relationship, medium to large sized SN-intention, PBC-intention and intention-behavior relationships, and a small to medium sized PBC-behavior relationship. As for the explained variances, intention normally explained between 19 percent and 38 percent of the variance in future behavior. Attitudes together with SN accounted for 33 percent to 50 percent of the variance in intention. The explained variance in intention could be increased by 5 percent to 12 percent and the explained variance in behavior could be increased by 2 percent to 12 percent over and above intention by adding PBC into the model. Despite considerable supports for the TPB constructs in predicting intention and behavior, it is also apparent that the TPB still leaves a substantial proportion of unexplained variance in intention and behavior. So other conceptual factors besides the TPB constructs should be considered. Even though Ajzen (1991) argued that any other variable external to the TPB model could have only an indirect effect on intention mediated by attitude, SN, or PBC, several studies on pro-environmental behavior have extended the TPB and successfully improved the explanatory power of the model. One of such additional factors that possess particular motivational power is personal norm (PN). Personal norm, which is also called moral norm or perceived moral obligation, reflects the individual's perception of the moral correctness or incorrectness of performing a particular behavior (Ajzen, 1991) and, according to Ajzen, takes into account "personal feelings of . . . responsibility to perform, or refusal to perform, a certain behavior" (p. 199). Several studies on pro-environmental behavior have supported the significance of adding PN into the TPB model. For example, Harland, Staats, and Wilke (1999) reported that the explained variance of intention could be increased by 1 to 10 percent by adding personal norm into the model. Moreover, Thøgersen and Ölander, (2006) found a very strong relationship between PN and organic food purchasing behavior. Two meta-analyses in the pro-environmental behavior domain confirmed the contribution of PN in improving the explanatory power of the TPB (Bamberg and Moser, 2007) and reported a large-sized PN-intention relationship (Bamberg and Moser, 2007) and a medium to large sized PN-behavior relationship (Gardner & Abraham, 2008; Bamberg and Moser, 2007).