["Economics &Politics, Volume 38, Issue 1, Page 46-61, March 2026. ", "\nABSTRACT\nWhy do interest groups with contrasting interests and policy goals work together? I present a theory of collaborative policy production and show that interest groups can achieve higher policy gains through collaboration, even though their ideal policy goals may diverge significantly. To test theoretical results, I introduce original measurement strategies that reveal systematic patterns in which firms and environmental groups invest in joint efforts to improve fine‐grained details of policy to achieve greenhouse gas emissions targets. The analysis, using public comments spanning 2010–2020, demonstrates that comments written jointly by environmental groups and firms contain more information that can contribute to the quality of policy implementation than individual efforts alone, despite compromises on policy preferences. These findings highlight the hidden dynamics of regulatory politics, wherein divergent political goals are reconciled for high‐quality policy implementation.\n"]