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 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.Keywords Bureaucratic institutional design · Public local health authorities · Consolidation and decentralization of local health authorities · Italian NHS JEL Classification D73 · H75 · I18 · L32 Would you say it is normal to have regions with 7 provinces and 22 Local Health Authorities? […] In my opinion, the idea of regions with 7 provinces and 22LHAs is an aberration. So if in agreement with the regions, since this task falls within their responsibilities, we can at last cut the number of managerial positions in the LHAs and apply 'standard costs' throughout, so that the proverbial needle has to cost the same in Calabria as in Lombardy, I would say this is a good thing. (Matteo Renzi, Italian PM, 10th April 2015, http://www.gover no.it/ media /consi glio-dei-minis tri-n58/619, 5:25-6:20; our translation)