I Hope Someday You’ll Join Us: Policy Core Beliefs and Social Identities Driving Sustainable Transport Policy

The city of Frankfurt/Main is one of Europe's financial market centers and at the same time one of the most important transport hubs in Europe. As a consequence, the overall transport system is overloaded both by regional and national transit traffic and by the traffic load caused by commuters and tourists. To address this problem, transport policy of the metropolis is increasingly oriented towards avoiding traffic and shifting traffic flows to more environmentally friendly modes of transport. In addition, the volume of traffic is to be reduced through parking space management concepts that are promoted by specific actor groups. However, what drives these actor groups in their behavior to promote sustainable transport policy and which factors enable their cooperation is yet understudied. The Advocacy Coalition Framework (ACF) emphasizes the central role of beliefs as causal drivers of political behavior (Jenkins-Smith et al., 2018). The studies concluded that a similarity in beliefs favors coordination and coalition building. By contrast, the main idea of the social identity theory and its adaption to social identities in the policy process (SIPP) is that the subjective belonging, positive evaluation and emotion to a group explain policy preferences (Hornung et al., 2019). Matching policy preferences can be an expression of common identities, because policy preferences define a group in a prototypical sense. Individuals who identify with a group adopt the preferences of that group as part of their own social identity. So far, only a few conceptual empirical studies exist on the sharing of common preferences in different social groups. Existing research offers several explanations and some empirical evidence, mostly related to partisan identity (González et al., 2008). The question of how belonging to different social groups affects the formation of policy preferences with regard to transport policy is of importance for policy process research, policy analysis, and political psychology. Clarifying this relationship helps to explain the group dynamics of political actors in local transport policy. Do they pursue their goals based on shared beliefs or shared identities? Or, do matching preferences result from social group membership? Answering these questions helps to better understand policy actors’ behavior and the way in which social identities and policy preferences effect sustainable transport policy.