| Abstract: |
There exists a long-standing debate about the influence of ideology in
economics. Surprisingly, however, there is no concrete empirical evidence to
examine this critical issue. Using an online randomized controlled experiment
involving economists in 19 countries, we examine the effect of ideological
bias on views among economists. Participants were asked to evaluate statements
from prominent economists on different topics, while source attribution for
each statement was randomized 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. Using a
model of Bayesian updating we examine two competing hypotheses as potential
explanations for these results: unbiased Bayesian updating versus
ideologically-biased Bayesian updating. While we find no evidence in support
of unbiased updating, our results are consistent with biased Bayesian
updating. More specifically, we find that changing/removing sources (1) has no
impact on economists’ reported confidence with their evaluations; (2)
similarly affects experts/non-experts in relevant areas; and (3) affects those
at the far right of the political spectrum much more significantly than those
at the far left. Finally, we 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. |