Erat and Gneezy (2012) conduct an experiment to test whether people avoid lying in a situation where doing so would lead to a Pareto improvement. They conclude that many people exhibit such a "pure lie aversion." I argue that the experiment does not provide a reliable test for such an aversion,...

In experiments which measure subjects' beliefs, both beliefs about others' behavior and beliefs about others' beliefs, are often correlated with a subject's own choices. Such phenomena have been interpreted as evidence of a causal relationship between beliefs and behavior. An alternative...