The author explores a new instrument for public-private partnership that was devised recently in the United Kingdom. The Social Impact Bond (SIB) is an innovative solution that aims to bring together the public administration, social finance and the non-profit sector. Many structural differences prevent its assimilation with the concessione di servizi; a comparison with this tool ends up, rather, emphasizing SIBs’ autonomy and originality. SIBs certainly have some advantages that resolve, at least partially, the problems relating to the use of private law in administrative law, but the complexity of the economic operations involved constitutes a specific limit. Finally, its origins in the contractual freedom of individuals, and the participation of public administrations as a veritable
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