Replication Data for: Regression Discontinuity Designs Based on Population Thresholds: Pitfalls and Solutions

In many countries, important features of municipal government (such as the electoral system, mayors' salaries, and the number of councillors) depend on whether the municipality is above or below arbitrary population thresholds. Several papers have used a regression discontinuity design (RDD) to measure the effects of these threshold-based policies on political and economic outcomes. Using evidence from France, Germany, and Italy, we highlight two common pitfalls that arise in exploiting population-based policies (compound treatment and sorting) and we provide guidance for detecting and addressing these pitfalls. Even when these problems are present, population-threshold RDD may be the best available research design for studying the effects of certain policies and political institutions.在诸多国家，市级政府的关键特征（如选举制度、市长薪酬、议员人数），取决于该市级行政区的人口是否高于某一任意划定的人口阈值。已有多项研究采用断点回归设计（Regression Discontinuity Design，RDD），测算这类基于人口阈值的政策对政治与经济结果的影响。本文依托法国、德国与意大利的实证证据，揭示了在利用基于人口的政策开展研究时常见的两类陷阱：复合处理效应与排序偏误，并为检测和应对此类陷阱提供了规范指引。即便存在上述两类问题，基于人口阈值的断点回归设计仍是研究特定政策与政治制度效应的最优可行研究设计方案。