Private Provision of Public Goods: Applying Matching Estimators to Evaluate 'Direct Payments' for Tropical Forest Conservation

世界在遏制生态系统破坏方面几乎没有取得什么进展。长期以来，经济学家一直认为，全球自然生态系统领域的衰落在很大程度上反映了未能建立机构，将完整生态系统的公共价值内化到使用这些生态系统的组织和个人内部。这一论点意味着，如果私人土地所有者和管理者在保护本地生态系统时为他们提供的公共利益获得报酬，社会就可以保护生态系统。根据经济学家的建议，直接支付保护费用在发达国家和发展中国家都已成为一种越来越受欢迎的政策工具。值得注意的是，缺乏关于这些付款对保护的影响的经验证据。本项目的目标是使用项目评估领域的匹配方法，对保护资金进行严格和系统的实证评估。其假设是，对保护热带森林的直接支付会导致受保护森林面积的净增加。这项建议是一项试点研究，将提供这一假设的初步测试，并开发全面项目评估的方法。作为最成熟和最著名的热带森林支付计划，哥斯达黎加的PSA(PSA)为评估直接支付作为保护政策工具的潜力提供了一个独特的机会。然而，PSA是一个非实验性(非随机化)的现实世界程序，因此评估其对土地所有者行为的影响并不是微不足道的。“处理”组(有PSA合同)和“对照”组(没有PSA合同)之间的森林面积差异(在这种情况下是期望的结果)可能完全归因于PSA，也可能是这两个组之间系统性差异的结果。这项初步研究将作为应用最先进的微观计量经济学方法的概念验证和预试，从项目评估(倾向-分数匹配)到生态系统保护的直接支付。在一种结合定性和定量方法的迭代研究方法中，该项目将(1)详细了解该计划是如何随着时间的推移在实践中以及正式地执行的(例如，接受、拒绝或等待列入名单的申请，以及取消或续签合同的过程)；(2)通过描述处理案例(参加PSA的土地所有者)和匹配的比较案例(不参加PSA的类似土地所有者)，深入了解土地所有者参与该计划的情况；(3)通过小样本的土地所有者提供“概念验证”匹配和参与评估；以及(4)数据收集、整合和分析的测试方法，这将是使用倾向分数或其他准实验估计器对PSA进行全国范围评估所需的测试方法。该项目由国际科学与工程办公室和经济项目共同资助。广泛影响：该项目通过开发生物物理数据与经济数据相关联的匹配方法的首次应用，为项目评估方法做出贡献。这种联系对于环境政策的评价是绝对关键的，但这两种类型的数据往往不能在相同的尺度上获得。这项试点研究将使调查人员能够评估在匹配方法中综合环境和经济数据的替代方法的准确性和成本效益。还没有尝试将最先进的经验性项目评估技术应用到保护政策的评估中。评估这些政策效果的适当方法将大大有助于提高其效力。更具体地说，调查人员将评估环保支出是否减少了森林砍伐，从而评估此类支出是否代表着实现环境目标的一种简单方式，到目前为止，这些目标花费了数十亿美元，但几乎没有记录在案的成功。该项目将为研究生提供宝贵的实地和分析经验，并为进一步研究奠定基础，为更多的学生提供机会。通过包括一名哥斯达黎加大学生，调查人员将帮助建立严格评估热带地区保护政策的能力。他们将把这个项目的经验和成果融入本科教学，并通过佐治亚州立大学的NSF资助的本科生暑期实习计划和北卡罗来纳州立大学的本科生研究计划为本科生的参与创造机会。

The world has seen little progress curbing the destruction of ecosystems. Economists have long argued that the global decline in the area of native ecosystems largely reflects a failure to create institutions that internalize the public values of intact ecosystems within the organizations and individuals that use these ecosystems. This argument implies that society can conserve ecosystems if private landowners and managers are paid for the public good they provide when they conserve native ecosystems. Based on the advice of economists, direct conservation payments have become an increasingly popular policy instrument in both developed and developing nations. Empirical evidence on the impact of these payments on conservation is notably lacking. The objective of this project is to conduct a rigorous and systematic empirical evaluation of conservation payments, using matching methods from the program evaluation field. The hypothesis is that direct payments for conservation of tropical forest result in a net increase in the area of protected forest. This proposal is for a pilot study that will both provide an initial test of this hypothesis and develop the methods for a full scale program evaluation.As the best established and best known payment initiative for tropical forests, Costa Rica's Programa de Pago de Servicios Ambientales (PSA) provides a unique opportunity to evaluate the potential of direct payments as a conservation policy tool. The PSA, however, is a non-experimental (nonrandomized) real-world program, and thus estimating its effect on landowner behavior is not trivial. Differences in forest area (the environmental public good that is the desired outcome in this case) between the "treatmen" (with PSA contracts) and "control" (without PSA contracts) groups may be entirely attributable to the PSA or may be a result of systematic differences between the groups. This pilot study will serve as proof-of-concept and pre-test for application of state-of-the-art micro-econometric methods from program evaluation (propensity-score matching) to direct payments for ecosystem conservation. In an iterative research approach that integrates qualitative and quantitative approaches, this project will (1) develop detailed understanding of how the program has been implemented over time in practice as well as officially (e.g., process of accepting, rejecting, or wait-listing applications, and canceling or renewing contracts); (2) gain insight on landowner participation in the program by profiling treatment cases (landowners enrolled in PSA) and matched comparison cases (similar landowners not in PSA); (3) provide 'proof-of-concept' matching and estimation of participation with a small sample of landowners; and (4) test methodologies for the data collection, integration, and analysis that will be required for a nationalscale evaluation of PSA using propensity-score or other quasi-experimental estimators. This project is co-funded by the Office of International Science and Engineering and the Economics Program.Broader Impacts: This project contributes to program evaluation methods by developing the first applicationof matching methods in which biophysical data are linked with economic data. Such linking is absolutely critical for the evaluation of environmental policies, but the two types of data are often not available at the same scales. This pilot study will allow the investigators to evaluate the accuracy and cost-effectiveness of alternative methods for addressing the integration of environmental and economic data in matching methods. There has been no attempt to apply state-of-the-art empirical program evaluation techniques to the evaluation of conservation policies. Appropriate methods for evaluating the effects of these policies would help substantially in improving their effectiveness. More specifically, the investigators will assess whether conservation payments reduce deforestation and thus whether such payments represent a simple way of achieving environmental objectives that have so far cost billions of dollars with few documented successes. The project will provide invaluable field and analytical experience to a graduate student, as well as laying the groundwork for further research that will provide opportunities for additional students. By including a Costa Rican university student, the investigators will help build capacity for rigorous evaluation of conservation policies in the tropics. They will incorporate lessons and results from this project into undergraduate teaching, as well as creating opportunities for undergraduate participation through Georgia State University's NSF-funded Summer Internship program for undergraduates and North Carolina State University's initiatives for undergraduate research.