Believing that social change is possible: Collective efficacy to promote engagement and mobilization of non-Roma as allies Urbiola, Ana López-Rodríguez, Lucía Torres-Vega, Laura Poslon, Xenia Daniela Lášticová, Barbara Pántya, József Szekeres, Hanna Kende, Anna Allies Collective action Collective efficacy Roma We analyzed the effect of collective efficacy on mobilizing allies for Roma rights and the role of legitimizing ideologies and perceived discrimination as moderators. In an online experiment, pooling two samples of non-Roma Hungarians (n = 397) and Spaniards (n = 339), participants were randomly assigned to a high (vs. low) efficacy condition and reported their perceived collective efficacy, collective action intentions, and participation for supporting Roma. Pooled analyses showed that participants were more willing to take action in the high (vs. low) efficacy condition, although meritocracy beliefs moderated the effects. In a second study in Slovakia (n = 454), with a control condition, we found indirect effects of the manipulation of collective efficacy, supporting the idea that decreasing perceived collective efficacy predicts lower collective action intentions and participation. In a third study in Hungary (n = 382), we disentangled collective efficacy from social norms and found indirect effects via perceived collective efficacy. Participants in the low efficacy condition (vs. high efficacy or control) perceived less collective efficacy as allies, which in turn was associated with lower collective action. We discuss the conceptualization of collective efficacy in experimental studies and its implications for the mobilization of equality. 2025-09-05T10:04:50Z 2025-09-05T10:04:50Z 2025-05-09 journal article Urbiola, A., López-Rodríguez, L., Torres-Vega, L. C., Poslon, X.-D., Lášticová, B., Pántya, J., Szekeres, H., & Kende, A. (2025). Believing that social change is possible: Collective efficacy to promote engagement and mobilization of non-Roma as allies. British Journal of Social Psychology, 64, e12895. https://doi.org/10.1111/bjso.12895 https://hdl.handle.net/10481/106097 10.1111/bjso.12895 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional John Wiley & Sons, Ltd.