We formulate the portfolio choice problem as a robust control problem under uncertainty or ambiguity aversion. By considering a stochastic investment opportunity set, we derive optimal robust portfolio rules in the cases of one and two risky assets. With two risky assets and ambiguity structure...

We examine information provision as a public policy instrument when products generate damages to consumers as well as environmental externalities. We show that information provision dominates taxation in terms of welfare, if information can be provided at low cost. This is because a uniform tax...