I have examined four basic property-based approaches to environmental protection (defined in terms of avoiding the tragedy of open access): public/state property, mixed public/state and private/individual property, pure private/individual property, and common property. Each approach has proven useful for resource conservation in some circumstances. None, however, has proven optimal for averting the tragedy of open access in every circumstance. Hence, this book's mantra: there is no universal, first-best property-based solution for environmental protection in this second-best world.

The next task is to assess the myriad factors that explain property regime choice in various ecological, technological, institutional, and economic circumstances. The objective is not to develop a normative theory, or even to generate useful predictions (although that would be a welcome consequence), but to understand and appreciate the complexities of property regime choice. This chapter offers an informal model that is, of necessity, rudimentary. To elaborate a fully fledged model for selecting property-based regimes would require an entire book of its own, if it could be done at all.

Section 1 of the chapter sets out the informal model and compares it with models offered by other authors. Section 2 introduces various complicating factors – everything from resource location and size to historical contingency and ideology – that limit the normative and predictive capability of any theoretical model.