Collaborative Research: Policy Analysis by Revealed Preference: With an Application to Food Security

世界各国政府将预算的很大一部分用于公共部门提供私人物品。因此，理解现金和实物再分配之间的权衡是政府政策的核心。例如，实物再分配可能会潜在地减少选择，从而降低受惠者的福利，但如果纳税人有家长式的偏好，并且更关心防止饥饿而不是穷人的其他愿望，则可能会增加纳税人的福利。pi提出了一项严格的实验研究，以估计(i)受益人对等额现金和实物转移的偏好，（ii）现金和实物转移对营养的相对影响，以及（iii）受益人对实物福利的评估。该设计允许人们测量受益人偏好（使用使用率）以及现金与实物福利对营养的因果影响（使用提供的随机分配来估计治疗意图和治疗对营养的影响）。此外，pi为额外随机选择的家庭提供了将其实物福利换取实验性变化的现金转移的选择，这使得可以估计在不同价格下对现状的需求，并量化受益人从相对于现金转移的实物福利中获得的消费者剩余（或损失）。在方法上，pi整合了主导现代政策评估的两种范式，一种基于影响，另一种基于揭示的偏好。此外，通过以随机变化的价格衡量消费，这些指数是第一批利用实验数据估计公共提供的私人物品的个人层面受益者估值的机构。揭示的偏好方法的独特之处在于，它使人们能够理解和适应受益人对现金和实物福利偏好的异质性，从而减少在诸如穷人粮食安全等关键领域进行政策试验的政治和道德风险。

Governments around the world spend large shares of their budgets on the public provision of private goods. Understanding the tradeoffs between redistribution in cash and in kind is thus central to government policy. For example, redistributing in-kind may potentially reduce choice and thus lower recipients' welfare, but may increase taxpayers' welfare if they have paternalistic preferences and care more about preventing hunger than about the other aspirations of the poor. The PIs propose a rigorous experimental study to estimate (i) beneficiary preferences over equally-valued cash and in-kind transfers, (ii) the relative impact on nutrition of cash and in-kind transfers, and (iii) beneficiary valuation of in-kind benefits. This design allows one to measure both beneficiary preferences (using the take up rate) as well as the causal impact of cash vs. kind benefits on nutrition (using the random assignment of the offer to estimate both intent-to-treat and treatment-on-treated effects on nutrition). Further, the PIs offer additional randomly selected households the option to exchange their in-kind benefits for an experimentally varied cash transfer, which allows to estimate the demand for the status quo at various prices and to quantify the consumer surplus (or loss) beneficiaries obtain from in-kind benefits relative to cash transfers. Methodologically, the PIs integrate in one design the two paradigms that have dominated modern policy evaluation, one based on impacts, the other based on revealed preferences. In addition, by measuring take-up at randomly varied prices, the PIs are among the first to estimate individual-level beneficiary valuations of publicly-provided private goods using experimental data. The revealed preference approach is unique in enabling one to understand and accommodate heterogeneity of beneficiary preferences over cash and in-kind benefits, thereby reducing the political and ethical risks of policy experimentation in a critical area such as food security for the poor.