Additionality Violations in Agricultural Payment for Service Programs: Experimental Evidence
定义了生态系统服务补贴项目的完美额外性，并通过公共物品博弈实验发现大量补贴活动不具有额外性，识别出“白拿钱”效应和挤出效应两种违规来源，补贴设计和管理实践替代性影响额外收益。
This article defines perfect program additionality (PPA) for payment for ecosystem services subsidy programs and formalizes potential violations of PPA. PPA is examined for multiple subsidy programs in an experimental setting using a variant of the common public good game. A large proportion of subsidized activities are found to be nonadditional. Further, two sources of nonadditionality are identified and tested for: the pay-for-nothing effect and crowding-out. The extent to which subsidies generate truly additional benefits is a function of both the design of the subsidy program and, crucially, whether the incentivized best management practice acts as a substitute for other best management practices. <i></i>