摘要:As we consider the potential for expanding water markets as a means to help prevent water shortages, it is clear that there is resistance to such an expansion. This resistance should not be surprising given that there are likely to be both gainers and losers from expanded water markets. This papers shows that there are a number of potential market failures when water markets are expanded and that these failures are important to different stakeholder groups. These failures result from both technical and pecuniary externalities. If markets are to expand beyond the local level, new institutional arrangements will be needed that help reduce the negative impacts of the different market failures. In the past a number of institutional arrangements have been used by different stakeholder groups to block trading. We review some of these arrangements as well as institutional arrangements that can work to promote market expansion by mitigating market failures or by compensating damaged parties.