Jonathan Crowe (The University of Queensland - T.C. Beirne School of Law) has posted Law Without the State (Policy, Vol. 30, No. 2, pp. 7-11, 2014) on SSRN. Here is the abstract:
Could there be law without the state? This strikes many people as a strange question. Law is so closely associated today with the edicts of government authorities that it is hard to disentangle the two ideas. This article begins by exploring the conception of law that underpins this mindset. It offers an alternative understanding of law that makes it possible to conceive of a legal order without state authority. The article then asks what legal institutions might look like in the absence of the state and discusses some challenges to law in a stateless society. I argue that it is at least plausible to think that stable sources of legal order could be maintained in a stateless environment. This conception of law without the state provides a useful framework for thinking critically about the limitations of current state-centred legal institutions.
For another take on law without the state, see Randy E. Barnett, The Structure of Liberty: Justice and the Rule of Law.