Key drawbacks include the complexity of the contract required to define the operator's activities. Governments also need to upgrade their regulatory capacity in relation to tariffs and performance monitoring. Further, the long term of the contracts (necessary to recover the substantial investment costs) complicates the bidding process and contract design, given the difficulty in anticipating events over a 25-year period. This drawback may be countered by allowing a periodic review of certain contract terms in the context of the evolving environment. There is additional risk that the operator will only invest in new assets where it expects payback within the remaining period of the contract unless provisions for these events are set out in the contract. Because of the long-term, comprehensive nature of the contracts, they can be politically controversial and difficult to organize. It is argued that concessions provide only limited competition given the limited number of qualified operators for a major infrastructure network. There is also concern that concessions not set out monopoly terms but provide room for additional operators where this is in the best interest of certain groups of consumers and the concessionaire cannot provide equivalent service.