HEDGING IN INCOMPLETE MARKERS WITH HARA UTILITY

Citation
D. Duffie et al., HEDGING IN INCOMPLETE MARKERS WITH HARA UTILITY, Journal of economic dynamics & control, 21(4-5), 1997, pp. 753-782
Citations number
32
Categorie Soggetti
Economics
ISSN journal
01651889
Volume
21
Issue
4-5
Year of publication
1997
Pages
753 - 782
Database
ISI
SICI code
0165-1889(1997)21:4-5<753:HIIMWH>2.0.ZU;2-X
Abstract
In the context of Merton's original problem of optimal consumption and portfolio choice in continuous time, this paper solves an extension i n which the investor is endowed with a stochastic income that cannot b e replicated by trading the available securities. The problem is treat ed by demonstrating, using analytic and, in particular, 'viscosity sol utions' techniques, that the value function of the stochastic control problem is a smooth solution of the associated Hamilton-Jacobi-Bellman (HJB) equation. The optimal policy is shown to exist and given in a f eedback form from the optimality conditions in the HJB equation. At ze ro wealth, a fixed fraction of income is consumed. For 'large' wealth, the original Merton policy is approached. We also give a sufficient c ondition for wealth, under the optimal policy, to remain strictly posi tive.