Before debating the when and how of intervention, the article defines market
failure, emphasizing the need to consider the full array of constraints that combine
to make a market work imperfectly. The various reasons for market failure are discussed
and set in the context in which credit markets function in developing countries.
The article then looks at recurrent problems that may be cited as failures of
the market justifying intervention. Among these problems are enforcement; imperfect
information, especially adverse selection and moral hazard; the risk of bank
runs; and the need for safeguards against the monopoly power of some lenders.
The review concludes with a discussion of interventions, focusing on the learning
process that must take place for financial markets to operate effectively.