placebo-test

Difference-in-Differences analysis of refugee inflows and crime rates in German regions (2010–2020)

Predicting placebo response using machine learning on psychological, personality, and clinical trial features.

DID 安慰剂检验的结构化 Stata 工作流（陈强/齐霁/颜冠鹏 2025 实践指南）。覆盖时间/空间/混合/外部四类 placebo，TWFE 默认、CSDID 升级。