When does a public–private partnership (PPP) lead to inefficient cost management? Evidence from South Korea’s urban rail system

This paper investigates the impact of a public–private partnership (PPP) on the operational cost-efficiency of South Korea’s urban rail system. Seoul’s line 9, which is operated by a PPP, was compared with Seoul Metropolitan Rapid Transit (SMRT) which is entirely run by the public sector. Overall, no evidence was found that private operation led to clear and significant declines in costs to the public. Private shareholders, on the other hand, experienced a surprisingly high rate of return. The author explains why two characteristics defining a typical PPP—activity bundling and public–private risk-sharing—were behind this unintended outcome and makes suggestions to prevent other governments experiencing similar problems.