ABSTRACT The article employs a model of interdependency of institutional choices and seeks to investigate the determinants of the provision and production of bus transportation services. We find that municipal population size and low levels of debt are the main drivers of service provision. The decision to cooperate in the provision of bus services is associated with municipalities that have lower levels of financial autonomy. Lastly, we find that larger municipalities and those not run by center left-wing mayors are more likely to opt for the externalization of bus services, either to municipal corporations or to private providers.