In Making a Market, Jean Ensminger analyzes the process by which the market was introduced into the economy of a group of Kenyan pastoralists. Professor Ensminger employs new institutional economic analysis to assess the impact of new market institutions on production and distribution, with particular emphasis on the effect of institutions on decreasing transaction costs over time. This study traces the effects of increasing commercialization on the economic well-being of individual households, rich and poor alike, over considerable time and analyzes the process by which institutions themselves are transformed as a market economy develops. This case study points out the importance of understanding the roles of ideology and bargaining power--in addition to pure economic forces, such as changing relative prices--in shaping market institutions.