Informal Insurance and Sustainable Management of Common‐Pool Marine Resources in Ha'apai, Tonga

This study reports onto coastal fisheries, in the island group of Haa'pai in the Kingdom of Tonga. On one island, Lofanga, the fishery is still sustainably used; on a neighboring island, 'Uiha, it is overused. None of the rules and regulations discussed in the literature is implemented in the island of Lofanga, Tonga. The two islands feature a similar parametric situation including natural regeneration, thus fulfilling the ceteris paribus condition. The subsequent analysis shows that the presence of the Lofanga informal insurance system sets incentives for Lofanga fishermen which induce a sustainable use of their coastal fishery while the fishery is stressed by overexploitation. The conclusion from the analysis is that onshore informal insurance rules can be a substitute for rules governing offshore fishing activities in securing sustainability of non-exclusive resource use.