Natural quasi-experiments can separate media event effects from preexisting differences

Evidence

In order to test priming, we partitioned the Form A sample into two groups: the first was comprised of the respondents who happened to have been interviewed before the 25 November revelations (N=714); the second was made up of those who happened to have been interviewed afterward (N =349). Respondents interviewed on 25 November were excluded. Initial comparisons revealed that the pre-revelation and postrevelation groups were essentially indistinguishable across a variety of demographic and political comparisons, including education, race, age, gender, employment status, family income, partisanship, interest in politics, and ideological self-identification. This means that whatever differences between groups we might detect in public opinion toward President Reagan can reasonably be attributed to the Iran-Contra revelations. — John T. Jost and Jim Sidanius, Political Psychology, 1583

Categorization

• XREF: A clean natural-experiment design — respondents split by whether they were interviewed before or after a news event. Echoes the regression-discontinuity-in-time logic used in media effects studies. — connects to: Natural experiments use policy changes to produce quasi-random variation in data — Philip Mirowski & Dieter Plehwe (eds.), The Road from Mont Pèlerin: The Making…, 1936
• DEEPTHINKING: The elegance here is that the researcher exploits interviewer scheduling randomness as an exogenous shock, achieving causal inference without manipulation. This is a model for how observational data can be converted into near-experimental causal claims.