Enough Already about "Black Box" Experiments: Studying Mediation Is More Difficult than Most Scholars Suppose

• Published in: The Annals of the American Academy of Political and Social Science Vol. 628; no. 1; pp. 200 - 208
• Main Authors: GREEN, DONALD P., HA, SHANG E., BULLOCK, JOHN G.
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA Sage Publications 01.03.2010; SAGE Publications; SAGE PUBLICATIONS, INC
• Subjects: Causal inference; Causality; Experiment design; Experimentation; Experiments; Intellectuals; Mediation; Norms; Observational research; Political campaigns; Political science; Research Design; Research methods; Scurvy; Social psychology; Social science research; Social sciences; Social Scientists; Statistical methods; Studies; Vitamin C; Voting behavior; causal mechanisms; mediation; causal inference; experiments
• ISSN: 0002-7162; 1552-3349
• DOI: 10.1177/0002716209351526

The question of how causal effects are transmitted is fascinating and inevitably arises whenever experiments are presented. Social scientists cannot be faulted for taking a lively interest in "mediation," the process by which causal influences are transmitted. However, social scientists frequently underestimate the difficulty of establishing causal pathways in a rigorous empirical manner. We argue that the statistical methods currently used to study mediation are flawed and that even sophisticated experimental designs cannot speak to questions of mediation without the aid of strong assumptions. The study of mediation is more demanding than most social scientists suppose and requires not one experimental study but rather an extensive program of experimental research.