Policymakers are highly involved with political issues, politically polarized, and knowledgeable about politics, all traits that could contribute to biased reasoning about policy evidence. In this paper, we explore whether policymakers are influenced by compelling policy evidence from ideologically disparate viewpoints, or whether they respond to evidence in an ideologically biased fashion. We conduct an experiment in which we randomly assign a sample of local policymakers to policy-relevant evidence that varies in quality as well as in its ideological implications. We find that there is a positive, statistically significant effect of strong evidence on policymakers’ attitudes and a smaller, positive (but not statistically significant) effect of weak evidence. We find no evidence of a moderating effect of ideology on the persuasive effects of either strong or weak evidence. We discuss the theoretical and practical implications of these findings as well as avenues for future research.
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