Partisan collaboration in policy adoption: An experimental study with local government officials

Partisanship plays a central role in the policy process, but its impact on the adoption of collaborative strategy by policymakers remains unknown. To fill this gap, I conducted a conjoint experiment involving municipal officials across the United States, examining the effect of co‐partisanship on policy collaboration and its moderating impact on collaborative attributes such as resource allocation, reciprocal trust, and policy outcome. The findings reveal that a collaborating partner's co‐partisanship status increases the likelihood of local policymakers adopting a program by 12.75 percentage points. Moreover, co‐partisan program proposals generally enhance the favorability of collaborative attributes. Finally, the consistency of the co‐partisanship effect across ideologies and various subgroups demonstrates that party identity is rooted in in‐group loyalty and fundamentally affects the collaborative process.