We propose a model where a regional government’s choice of the number of bureaucratic agencies operating in a region depends upon the degree of substitutability and complementarity of the bureaucratic services being demanded. We show that, if the government perceives the citizens’ demand as a demand for substitutable services, it will choose provision by two independent agencies. If the government perceives the citizens’ demand as a demand for complementary services, it will choose provision by a single consolidated agency. Exogenous shocks to the number of citizens amplify these incentives. Evidence from the Italian National Health Service (NHS) supports this hypothesis. Results show a positive effect of proxies of substitutable services on the number of regional Local Health Authorities (LHAs) and a negative effect of proxies of complementary services. The major immigration amnesties, taken as shocks to the number of citizens entitled to the service, magnify these effects
