Under what conditions can Payments for Environmental Services deliver sustainable improvements in welfare? Learning from a Randomized Control Trial

威尔逊·马尔东达多（Wilson Maldondado）看着他的牛一只接一只地死去。在威尔逊的记忆中，2010年玻利维亚的旱季是最糟糕的，在维拉蒙特斯有200头牛死亡，查科地区还有无数其他的牛死亡。但这并不是第一次长期干旱。2004年，古铁雷斯有5万多人受到影响，那里90%以上的玉米歉收。古铁雷斯有20个社区没有饮用水，甚至维拉蒙特斯镇也没有饮用水。威尔逊望着聚集在阿瓜拉格山脉上的云彩，心里纳闷，山脉离得那么近，查科河怎么会这么干燥。在整个拉丁美洲，可以为用户提供清洁水的流域往往必须支持额外的、有时是相互冲突的功能，例如农业和林业。事实证明，现有的监管框架往往无法调和这些相互冲突的需求。上游流域的农民除了砍伐他们的土地用于农业之外，往往没有其他经济选择。上游的水厂因此遭到破坏——通常是为了微薄的代价——奶牛进入河床喝水、觅食、小便和排便。上游流域农民的自给农业生产力低下，易受气候变化的影响。下游的市政水源受到污染，孩子们因腹泻而无法上学，泥沙堵塞了管道和水坝，像威尔逊·马尔多纳多这样支持农民的水坑干涸了。2003年在玻利维亚的Los Negros， Fundación Natura Bolivia （Natura）帮助启动了一种新的基于激励的节水模式：市政支付环境服务（PES）。这些项目基于两个公理：1)保护上游森林将有助于维持水供应的数量和质量；2)下游用水户需要为这种森林保护作出贡献。这些计划的关键属性是预防原则和地方机构建设和协调。从2003年6位农民同意保护465公顷森林的微不足道的开始，到现在有3万多名下游用户为保护3.5万公顷森林向1140户上游家庭提供补偿。这项研究将确定在何种条件下，这种小规模的环境服务支付（PES）计划能够提供可持续的福利改善。我们将采用一系列随机对照试验（RCT）：1。探索生态系统服务的支付如何支持玻利维亚查科地区的扶贫工作。玻利维亚的查科地区炎热干燥，贫困普遍存在，土著人民的土地是集体持有的，干旱是农业的主要制约因素。因此，玻利维亚的情况并不典型，实际上更像撒哈拉以南的非洲。因此，我们期望我们吸取的教训将适用于较不发达国家。2. 借鉴玻利维亚和其他安第斯山脉国家的经验教训和工具，评估市政主导的PES的有效性，以及随机对照试验方法在生态系统服务和扶贫干预方面的适用性。2 .我们将利用对秘鲁、哥伦比亚和厄瓜多尔的200名市政技术人员进行培训的项目，了解如何建立小规模的PES计划。我们将对外部投入和种子资本对PES发展的重要性进行有控制的评估。开发和测试可支持哥伦比亚环境部的随机对照试验评估工具包。我们将与政府的森林和生态系统服务指导局合作，帮助制定国家PES计划的监测和评估方案，确保将所有市政收入的1%投资于上游流域保护。这项建议的基本目标是评估在什么条件下环境服务付款能够实现可持续发展。第二个目标是开发一系列评估工具，以便在全球范围内应用，并帮助项目开发人员快速评估其减贫干预措施的有效性，从而提高其影响。

Wilson Maldondado watched his cattle die one by one. The 2010 Bolivian dry season was the worst in Wilson's memory, killing 200 cows in Villamontes and countless others across the Chaco. But it was not the first long drought. In 2004 more than 50,000 people were affected in Gutierrez, where more than 90 percent of the corn crop failed. In Gutierrez 20 communities had no drinking water, and even Villamontes town ran out. Wilson looked at the clouds gathering on the Sierra del Aguarague and wondered, with mountains so close, how the Chaco could be so dry. Across Latin America, the watersheds that could provide users with clean water often have to support additional and sometimes conflicting functions, such as agriculture and forestry. Existing regulatory frameworks have often proved unable to reconcile these conflicting needs. Upper watershed farmers often have no economic alternative other than to deforest their land for agriculture. Upstream Water Factories are thus destroyed-often for a pittance-and cows enter streambeds to drink, forage, urinate and defecate. The subsistence agriculture of upper watershed farmers is unproductive and susceptible to climate change. Downstream municipal water sources are contaminated, children miss school with diarrhoea, sedimentation blocks pipes and dams, and waterholes supporting farmers like Wilson Maldonado dry up. In 2003 in Los Negros, Bolivia, Fundación Natura Bolivia (Natura) helped initiate a new incentive based water conservation model: municipal payments for environmental services (PES). These projects are based on the twin axioms that 1) protecting upstream forests will help maintain water supplies in quantity and quality, and 2) downstream water users need to contribute to such forest protection. The key attributes of these schemes are the precautionary principle and local institution building and alignment. From humble beginnings in 2003, when 6 farmers agreed to protect 465 ha, more than 30,000 downstream users are now compensating 1,140 upstream families for protecting 35,000 ha of forest.This research will identify conditions under which such small scale Payments for Environmental Services (PES) schemes can deliver sustainable improvements in welfare. We will use a series of Randomized Control Trials (RCT) to:1. Explore how payments for ecosystem services can support poverty alleviation in the Bolivian Chaco. The Bolivian Chaco is hot and dry, poverty is widespread, the indigenous people's land is held communally, and drought is a major agricultural constraint. Conditions are thus not typical of Bolivia, and indeed are more like sub-Saharan Africa. We thus expect that lessons we learn will be applicable to less developed countries. 2. Take lessons and tools from Bolivia to other Andean countries, to evaluate the effectiveness of municipal-led PES, and the applicability of the RCT methodology for ecosystem service and poverty alleviation interventions. Taking advantage of an project that will train 200 municipal technicians from Peru, Colombia and Ecuador in how to set up small-scale PES schemes, we will undertake a controlled evaluation of the importance of external inputs and seed capital for PES development.3. Develop and test an RCT evaluation toolkit that can support the Colombian Ministry of the Environment. We are will work with the Government's Direction of Forests and Ecosystem Services to help develop a monitoring and evaluation program for the national PES scheme which ensure that 1% of all municipal revenues are invested in upstream watershed protection.The fundamental objective of this proposal is to assess under what conditions Payments for Environmental Services can deliver sustainable development. A secondary objective is to develop a series evaluation tools so that they can be applied globally, and which can help project developers quickly assess the effectiveness-and hence improve the impact-of their poverty reduction interventions.