Self-censorship on American university campuses is highest among students with the most moderate views — not simply among conservatives — according to a new working paper from the National Bureau of Economic Research (NBER).

Economists Peter Arcidiacono, Cory Dowd, and Matthew Lilley base their findings on survey data collected from students at a private elite college — a scope that leaves open how far the pattern extends to other kinds of institutions. Their results add nuance to a widespread concern in public debate that conservative voices are being stifled on campus. The study does find that conservatives self-censor at higher rates than liberals, but it also concludes that students occupying the ideological middle ground hold back the most. “Self-censorship is not simply about being conservative: it is students with the most moderate views who self-censor the most,” the paper states. For a debate that has largely centered on conservative expression, identifying moderates as the most reticent group gives the discussion an empirical reference point beyond the familiar left-right framing.

The authors associate this pattern with two factors: confidence and salience. Students who are more confident in their views, or who see an issue as especially important, tend to hold more extreme positions and to self-censor less. In that framing, whether a student speaks up reflects how firmly they hold a position and how much it matters to them, rather than ideology alone.

The data also reveal ideological asymmetries within individuals. The same student is more likely to self-censor on the views where they are relatively more conservative than on those where they are relatively more liberal. Conservatives are also far more likely than liberals to cite concerns about social exclusion as a reason for staying quiet, and they report self-censoring less once outside the university community.

Perceived marginality matters as well. Groups seen as marginalized self-censor less than majority groups, and the difference is widest on issues salient to those groups — for example, Black students on the Black Lives Matter (BLM) movement. Read together with the within-student asymmetries, the results describe silence as tied to specific issues and a student’s position relative to the majority view, rather than as a fixed trait of one political group.

The paper is available through the NBER working paper series, with an author profile for Peter Arcidiacono on the NBER website. NBER is a private, nonprofit research organization based in Cambridge, Massachusetts; its working papers circulate research ahead of formal publication and have not necessarily undergone peer review, so the findings could still change as the research moves through that process.

The findings were highlighted by the economics blog Marginal REVOLUTION.