The inequalities in conventional zoning-based policies leave urban-fringe jurisdictions unable to meet the growing demand for permanently preserved open space. Allocating marketable development rights (MDR) among all landowners treats this problem directly. It also leaves open the option of allowing the market to allocate land to undeveloped uses. A simple market model is used to develop a framework that describes the mechanics of such a program; it allows for comparison with other commonly considered policies. Several concerns policy makers have raised about a market in development rights are addressed. Alternative regulatory responses to perceived market failures are presented. It is suggested that and MDR program offers significant advantages over existing preservation efforts.