Based on the evaluation of over 1000 concessions/PPP from the 1990s to 2014, the paper presents the evolution and trends of the performance of PPP, with particular emphasis of PPP program and contract structure (defined by a number of key variables) as determinants of performance, and of the incidence and drivers and impact of renegotiations, and derives lessons and suggestions ala best practices for correcting and reforming (or launching when appropriate) PPP programs, accounting for country characteristics.