What is it about?

Governments and organizations worldwide have established behavioral insights teams advocating for randomized experiments as a critical tool to advancing human welfare. Recently, however, it has been suggested that people tend to find randomized experiments as less appropriate than the universal implementation of its underlying unobjectionable policies, while others have argued that such a common pattern does not exist. The goal of our research was to examine the existing evidence for such a common pattern of experiment aversion to determine its generalizability. In a nutshell, we find that experiment aversion does not appear to generalize, and therefore policymakers may not need to be concerned about using evidence-based practice more so than about universally implementing individual policies.

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Why is it important?

As previous authors have pointed out, individuals’ attitudes toward experiments matter not because these individuals decide on policy implementation, but because they affect policymakers’ decisions. Therefore, if policymakers anticipate a tendency for objections toward experiments, they may opt for universal implementations or conduct randomized evaluations in secrecy – neither of which is optimal.


We have great respect for the researchers and their work on both sides of the existing debate. Rigorous debate, where papers build on each other and together triangulate a research question is what science is about. Following the data without being wedded to a particular position is what drives scientific insight and knowledge creation. In that spirit, we do not see our paper to be the final word on the debate but a contributing part to an ongoing conversation and a summary of what we believe the data accumulated so far suggests. In previous papers published in PNAS, Meyer et al. (2019) and Heck et al. (2020) speculated about moderators of people’s tendency to object to experiments. Our data suggests more than that. That is, together with the previous evidence, our data suggests that there does not exist a common pattern of behavior consistent with experiment aversion (i.e. there does not appear to be a general tendency to object to experiments). Instead, it seems that sometimes people prefer experiments more, sometimes less, and sometimes they are indifferent between them and the universal implementation of its individual policies. Thus, whenever communicating a policy, it is useful to remember that there is no “neutral” language, and policymakers can and should be mindful of their communication choices and perhaps even test them.

Nina Mazar
Boston University

Read the Original

This page is a summary of: Experiment aversion does not appear to generalize, Proceedings of the National Academy of Sciences, April 2023, Proceedings of the National Academy of Sciences,
DOI: 10.1073/pnas.2217551120.
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