Elinor Ostrom pointed out significance of rule structures, and the need for institutional diversity in addressing commons problems.This is particularly true in relation to the governance of large-scale commons resources and one global commons that requires attention is the economic system.We share the institutional arrangements that generate economic benefits but neither the wealth generated by the system, nor the negative impacts, are shared equally.The result is an economic system focused on the privatisation of shared resources that generates inequalities around the globe. This paper explores the economic system as a ‘co-created’ commons.The paper brings together two broad strands of literature on commons: one arising from the public trust doctrine, and the other based on the economic characteristics of a good or service in terms of its access (‘excludability’) and consumption (‘subtractability’).The paper links these concepts with more recent work on ‘productive commons’, where shared resources are generated through collaborative activity, and ideas from evolutionary economics, which explore the economic system as a process and structure of rules, rather than as a series of transactions based on the allocation of property rights.Evidence is provided to support the argument that commons are an integral element of the economic system, and as a result account for some of its efficiencies and, where rule structures fail, for negative impacts on socio-economic and ecological systems.

This chapter explored the idea of leveraging property rights to enable either better decision making by stakeholders, usually by changing the ex ante information and incentives, or by re-allocating rights as originally suggested by Coase. We explored Hardin’s (in)famous ‘Tragedy of the Commons,’ from the economic perspectives of rivalry (aka subtractability) and excludability. We explored the impacts of observing the three states of rivalrous, non-rivalrous, and anti-rivalrous against both excludable and non-excludable, yielding six types of goods or services. Traditional property concepts, such as rules of first capture or first mover, could lead to inefficient use of resources. Demsetz's theory is that property rights could emerge, sua sponte, internalising externalities that follow from open access; that property rights enable communities to re-balance the impacts of Pigou’s externalities. Demsetz’s theory does not necessarily imply the establishment of private property rights. Again, the issues of rivalry and excludability came into view. Cooter and Ulen advocated that if property rights could be granted for various natural resources, including wildlife, it would benefit the efforts to protect and conserve those resources.