A public–private partnership (PPP, 3P or P3) is a cooperative arrangement between two or more public and private sectors,
typically of a long-term nature.
They are primarily used for infrastructure provision,
such as the building and equipping of schools, hospitals, transport systems,
water and sewerage systems. PPPs have been highly controversial as funding tools,
largely over concerns that public return on investment is lower than returns for the private funder.
It is closely related to concepts such as privatization and the contracting out of government services.
The lack of a shared understanding of what a PPP is makes the process of evaluating whether PPPs have been successful complex.
Evidence of PPP performance in terms of VfM and efficiency, for example, is mixed and often unavailable.
Common themes of PPPs are the sharing of risk and the development of innovation.