Who said or what said? Estimating ideological bias in views among economists

There exists a long-standing debate about the influence of ideology in economics. Surprisingly, however, there are very few studies that provide systematic empirical evidence on this critical issue. Using an online randomised controlled experiment involving 2,425 economists in 19 countries, we examine the effect of ideological bias among economists. Participants were asked to evaluate statements from prominent economists on different topics, while source attribution for each statement was randomised without participants' knowledge. For each statement, participants either received a mainstream source, an ideologically different less-/non-mainstream source, or no source. We find that changing source attributions from mainstream to less-/non-mainstream, or removing them, significantly reduces economists' reported agreement with statements. This contradicts the image economists have/report of themselves, with 82% of participants reporting that in evaluating a statement one should only pay attention to its content. Our analysis provides clear evidence for the existence of ideological bias as well as of authority bias among economists. We also find significant heterogeneity in our results by gender, country, PhD completion country, research area and undergraduate major, with patterns consistent with the existence of ideological bias.