Public utility planning and cost efficiency in a decentralized regulation context: the case of the Italian integrated water service

The reformed Italian water and sewerage industry has several distinctive features. It is based on a decentralized structure where local authorities are entitled to define detailed long‐term budget plans that claim to provide efficiency incentives to operating suppliers. Unlike previous studies, this paper analyzes the cost efficiency embedded in these budget plans to evaluate the actual capability of local regulators to adequately orientate firm performance. Several panel data cost frontier models were estimated that incorporate diverse specifications for inefficiency and unobserved heterogeneity terms. The results indicate that the decentralized planning mechanism applied in Italian water and sewerage industry regulation failed in fulfilling the declared goal and further highlights that the time‐invariant terms are the prevailing source of cost differences, which may conceal a structural component attributable to persistent inefficiency.