Abstract

A simple model was tested in which attitudinal factors and external conditions act in combination to influence behavior. The model predicts that behavior is a monotonic function of attitudes and external conditions and that the strength of the attitude-behavior relationship is a curvilinear function of the strength of the external conditions, with extreme values setting boundary conditions on the applicability of attitude models. The model also allows for interactions in which perceived costs enter into the attitudinal process. Evidence is taken from a natural experiment in recycling in which collection bins for curbside pickup had been provided to 26% of 257 survey respondents. Consistent with the model, main effects of attitudes and external conditions were found, as was an interaction effect in which the Schwartz norm-activation model predicted recycling behavior only for households without bins. Interactive models such as the one developed here can yield better policy-relevant analyses by clarifying the relationships between external and internal influences on behavior change.