In this paper we review some well-known simple models for portfolio selection under Knightian uncertainty, also known as ambiguity, and we compute a number of explicit optimal portfolio rules using elementary mathematical tools. In the case of a single period financial market, new results arise...

We consider a single-period financial market model with normally distributed returns and the presence of heterogeneous agents. Specifically, some investors are classical Expected Utility Maximizers whereas some others follow Cumulative Prospect Theory. Using well-known functional forms for the...

Starting from the theory of portfolio selection under Cumulative Prospect Theory (CPT) in a one period model, we firstly present some remarks connected with the violation of the so-called loss aversion in the case of power utility functions. The main contribution of this paper comes from the...

This note identifies and fixes a minor gap in Proposition 1 in Barberis and Huang (2008). Assuming homogeneous Cumulative Prospect Theory decision makers, we show that CAPM is a necessary (though not sufficient) condition that must hold in equilibrium. We support our result with numerical...

We study the connections between stochastic dominance and law invariant preferences. Whenever the functional that represents preferences depends only on the law of the random variable, we shall look for conditions that imply a ranking of distributions. In analogy with the Expected Utility...