The inevitability of leakages to other agents in the supply chain, and the difficulties of targeting have already been noted. In addition such measures may crowd out the development of private input markets, may lead to the over-use of inputs, and once introduced have historically proven difficult to rescind. Nevertheless, there has been renewed optimism that a new generation of so-called “smart” subsidies, by virtue of innovative design features, such as exit strategies, can deliver income benefits while limiting their known shortcomings (Dorward, 2009b). These arguments are considered in (OECD, 2010b).