Joining Forces or Going Solo? The Political and Economic Dynamics of Intermunicipal Cooperation

The emergence and dynamics of inter-municipal cooperation (IMC) remain complex despite extensive research. This study examines why and when municipalities engage in IMC across multiple services. Using data from Catalonia spanning a decade, we analyse both static and dynamic factors influencing IMC adoption. Our generalized linear mixed model reveals that population size, fiscal constraints, and political participation significantly affect cooperation patterns. Economies of scale are particularly relevant for services where cooperation is frequent, while their influence diminishes as economies of density are involved. The dynamic analysis using Cox proportional hazards models indicates that high public debt and low turnout accelerate IMC adoption. These findings enhance the understanding of IMC drivers and highlight the importance of distinguishing between service-specific, organizational, and political factors that influence the existence of cooperation versus those driving its timing. Our analysis across eight services confirms that no single delivery service approach fits all scenarios.