We experimentally test an endogenous-timing investment model in which subjects privately observe their cost of investing and a signal correlated with the common investment return. Subjects overinvest, relative to Nash. We separately consider whether subjects draw inferences, in hindsight, and use foresight to delay profitable investment and learn from market activity. In contrast to Nash, cursed equilibrium, and level-k predictions, behavior hardly changes across our experimental treatments. Maximum likelihood estimates are inconsistent with belief-based theories. We offer an explanation in terms of boundedly rational rules of thumb, based on insights about the game, which provides a better fit than quantal response equilibrium.

We use a second-price common-value auction, called the maximal game, to experimentally study whether the winner's curse (WC) can be explained by models which retain best-response behavior but allow for inconsistent beliefs. We compare behavior in a regular version of the maximal game, where the WC can be explained by inconsistent beliefs, to behavior in versions where such explanations are less plausible. We find little evidence of differences in behavior. Overall, our study casts a serious doubt on theories that posit the WC is driven by beliefs.