https://macropaperwarehouse.com/authors/soonwoo-kwon/Soonwoo KwonHugo -- gohugo.ioen-ushttps://macropaperwarehouse.com/papers/testing-mechanisms/https://macropaperwarehouse.com/papers/testing-mechanisms/<p>Kwon and Roth develop econometric tests for the &ldquo;sharp null of full mediation&rdquo;: the hypothesis that a treatment D affects an outcome Y only through a specified mechanism (or set of mechanisms) M, with no direct pathway. Rather than attempting the more demanding task of identifying average direct and indirect effects — which typically requires strong assumptions about how M is assigned — the paper asks whether full mediation is consistent with the data at all, and if not, how large the alternative mechanisms are.</p>