The requirement of positive marginal utility only makes it possible to derive a restricted twofund separation theorem for portfolio selection problems replacing the original separation theorem of Cass and Stiglitz (1970). We use our findings for a re-examination of the bias-in-beta problem in...

We consider investors with mean-variance-skewness preferences who aim at selecting one out of F different funds and combining it optimally with the riskless asset and direct stock holdings. Direct stock holdings are either exogenously or endogenously determined. In our theoretical section, we...

"Coherent" measures of a bank's whole risk capital imply a structure of a bank's optimal credit portfolio that is independent of its deposits and the expected deposit rate, of expected bankruptcy costs and of expected costs of regulatory capital. -- Basel II ; Regulatory Capital ; Coherent Risk...

We show analytically under quite general conditions that implied rates of return based on analysts' earnings forecasts are only a downward biased estimator for future expected one-period returns and therefore not suited for computing market risk premia. The extent of this bias is substantial as...

The most relevant practical impediment to an application of the Markowitz portfolio selection approach is the problem of estimating return moments, in particular return expectations. We analyze the consequences of using return estimates implied by analysts' dividend forecasts under the explicit...