Welfare Analysis of Changing Notches: Evidence from Bolsa Família
提出一个框架，利用两个充分统计量（新断点下方和旧断点下方的家庭数量变化）来评估断点改革的福利影响，并应用于巴西家庭补助金改革，发现其边际价值公共资金（MVPF）在0.90-1.12之间。
We develop a framework to bound the welfare impacts of arbitrarily large reforms to notches using two sufficient statistics: the change in the number of households located below the new notch and the change in the number of households located below the old notch. Our bounds hold in a wide class of models, highlighting a new way to use reduced-form bunching evidence for welfare analysis without making strong assumptions on the economic environment. We estimate these two statistics using a difference-in-difference strategy for a reform to the antipoverty program Bolsa Família, finding that the reform’s MVPF is between 0.90–1.12.