With increasing frequency commentators have been urging greater reliance on the market mechanism to allocate resources in a variety of fields. There has been relatively little examination, however, of the extent to which decentralized mechanisms can be used to handle the controversial social problem of conflicts among neighboring landowners. Land development in urban areas is one of the most regulated human activities in the United States. In recent decades, public regulation of urban land has increased sharply in incidence and severity, but dissatisfaction with the physical appearance and living arrangements in American cities continues to grow. Despite the evident shortcomings of present public regulatory schemes, even those commentators who propose reliance on the market mechanism in other areas tend to concur with the prevailing view that increased public planning is the most promising guide for the growth of cities. This article advances a different thesis: that conflicts among neighboring landowners are generally better resolved by systems less centralized than master planning and zoning.