We relate time-varying aggregate ambiguity (V-VSTOXX) to individual investor trading. We use the trading records of more than 100,000 individual investors from a large German online brokerage from March 2010 to December 2015. We find that an increase in ambiguity is associated with increased...

We use cross-country microdata to analyse the risk taking of households in Europe and the US. Concerning the extensive as well as the intensive margin of risky assets, European households differ substantially from US households; but also inside Europe we document substantial differences....

We consider an investor who faces parameter uncertainty in a continuous-time financial market. We model the investor's preference by a power utility function leading to constant relative risk aversion. We show that the loss in expected utility is large when using a simple plug-in strategy for...

We examine asset allocation decisions under smooth ambiguity aversion when an investor has a prior degree of belief in an asset pricing model (e.g., the domestic CAPM). Different from a Bayesian approach, the investor separately relies on the conditional distribution of returns and on the...