This paper provides a coherent method for scenario aggregation addressing model uncertainty. It is based on divergence minimization from a reference probability measure subject to scenario constraints. An example from regulatory practice motivates the definition of five fundamental criteria that...

Despite well-known shortcomings as a risk measure, Value-at-Risk (VaR) is still the industry and regulatory standard for the calculation of risk capital in banking and insurance. This paper is concerned with the numerical estimation of the VaR for a portfolio position as a function of different...

We develop a transparent Bayesian approach to quantify uncertainty about linear stochastic discount factor models. We show that, for a Bayesian decision-maker, the model probability decreases with historical maximum in-sample Sharpe ratios and increases with model dimensions. We apply our...