Water pollution caused by aquaculture or agricultural activities negatively affects both the activity and downstream areas. A number of other upstream‐downstream problems (e.g. water use, industrial/municipal water source pollution, salinity zoning problems) are examples of similar negative externalities. Non‐point source pollution, which is either prohibitively costly or impossible to observe, is more feasible to identify, and hence mitigate at the aggregate level. We study experimentally the efficacy of two possible management systems: a centralised external, formal government‐led monitoring and control system; a self‐governing communication and informal system, both designed to manage shrimp farming, which generates a non‐point source pollution with upstream‐downstream externalities. Our results suggest that local communication and control outperforms the external monitoring and certification agency. These results, in conjunction with other relevant research, suggest that informal regulation and self‐governance among shrimp farmers can be highly successful in tackling the pollution problem.

中文翻译：

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正式与非正式系统缓解面源污染的实验研究

水产养殖或农业活动造成的水污染对活动和下游地区均产生负面影响。许多其他上游-下游问题（例如用水，工业/市政水源污染，盐分分区问题）就是类似的负面外部性的例子。非点源污染的成本过高或难以观察，因此更易于识别，因此可以从总体上减轻污染。我们通过实验研究了两种可能的管理系统的功效：一个集中的，外部的，由政府主导的正式监控系统；一个自治的沟通和非正式系统，旨在管理虾类养殖，这会产生上游到下游外部因素的面源污染。我们的结果表明，本地沟通和控制胜过外部监控和认证机构。这些结果与其他相关研究相结合，表明对虾养殖者之间的非正式监管和自治可以在解决污染问题方面取得巨大成功。