Purpose
– The theory of planned behavior (TPB) served as a framework for identifying major antecedents of everyday green purchasing behavior and for determining their relative importance.
Design/methodology/approach
– The German market research institute GfK provided data (n = 12,113) from their 2012 household panel survey. A two-step structural equation modeling approach was applied to test both the measurement and the structural model.
Findings
– Willingness to pay (WTP) was the strongest predictor of green purchasing behavior, followed by personal norms. The impact of attitude is insignificant. This implies an attitude – behavior gap.
Research limitations/implications
– Individuals overestimate their self-reported WTP and behavior, which suggests that the share of explained variance is in reality lower. It has to be doubted whether consumers are objectively able to judge products by their environmental impact. Even if consumers are willing to buy a “greener” product, their subjective evaluation might be incorrect. Further research should be based on actual purchasing data. In addition, the attitude – behavior gap should be scrutinized by further research to identify further barriers to green consumption.
Practical implications
– Consumers need to be aware that their consumption behavior can make a difference. They have to value the benefits of green products and understand why these are priced higher. Firms can apply pricing and promotional strategies addressing personal norms and inducing a higher WTP to capitalize on the opportunities of the green market segment.

Originality/value
– The study integrates WTP and personal norms as critical predictors into the TPB and furthermore expands the extant literature on green purchasing behavior to cover daily consumer goods extending beyond organic food. This enhances understanding of the structure of the constructs and determines their relative importance.