The suboptimal size of municipalities is often a challenge for service delivery due to scale limitations. Intermunicipal cooperation (IMC) has expanded as an alternative to top-down amalgamations, offering a more flexible and typically voluntary approach. Many studies have been devoted to understanding the driving factors of IMC, providing static empirical evidence on the characteristics of cooperating municipalities. This article contributes to the literature with a dynamic analysis of the drivers of cooperation, using a Cox proportional hazards model over a long period and a very large sample of municipalities in Catalonia. This dynamic analysis unravels the direction of the causal relationship in complex relationships such as fiscal restrictions or political legitimation with cooperation. Furthermore, as we have data from eight relevant local services, we improve both the theoretical and empirical analysis of cooperation dynamics based on the characteristics of the services.
