We analyze the portfolio planning problem of an ambiguity averse investor. The stock follows a jump-diffusion process, and there is ambiguity about the drift of the stock and the intensity of jumps. The consequences of ambiguity with respect to jump and diffusion risk are by no means the same....

We analyze the optimal stock-bond portfolio under both learning and ambiguity aversion. Stock returns are predictable by an observable and an unobservable predictor, and the investor has to learn about the latter. Furthermore, the investor is ambiguity-averse and has a preference for investment...

Traditional life-cycle models conclude that individuals should be fully invested in stocks when young -- in stark contrast to observed stock holdings -- and then gradually replace stocks with bonds as retirement is approaching. We show that a carefully specified and calibrated model of...

We analyze the optimal stock-bond portfolio under both learning and ambiguity aversion. Stock returns are predictable by an observable and an unobservable predictor, and the investor has to learn about the latter. Furthermore, the investor is ambiguity-averse and has a preference for investment...

We analyze the portfolio planning problem of an ambiguity averse investor. The stock follows a jump-diffusion process. We find that there are pronounced differences between ambiguity aversion with respect to diffusion risk and jump risk. Ignoring ambiguity with respect to jump risk causes larger...