static optimal portfolio choice in the mean-variance framework under different uncertain exit-times for each risky asset

In the static optimal portfolio choice in the mean-variance framework the exit-time for each asset is deterministic which is the investment time horizon of the investor too. however, the investor may be forced to exit the market at an uncertain time which terminates the investment in all assets simultaneously. this issue is investigated by manyauthors in various settings. this paper considers separated uncertain exit-time for each asset,i.e. asset exit-times are not simultaneous. so this model extends the previous model.