The movement towards the privatization of corrections in the United States is a result of the convergence of two factors: the unprecedented growth of the US prison population since 1970 and the emergence out of the Reagan era of a political environment favorable to free-market solutions. Since the first private prison facility was opened in 1984, the industry has grown rapidly; gross revenues exceeded $1 billion in 1997. This paper examines the industry''s growth in the US in recent decades, and its current scope. The evidence for and against claims that private prisons can realize gains in efficiencyare weighed, and implications of privatization for other public values including safety, justice, and legitimacyare examined.