以下是引用gzmengdan在2008-12-11 21:47:00的发言:一个投资者拥有财富x,有可能遭受损失,遭受损失的概率为p。他可以购买保险,如果购买保险的金额为w,则当损失发生是可以获得2w的赔偿,如果没有发生则为0。效用函数为u(x)=-e-rx,r>0。
问:1、该投资者愿意购买的保险金额为多少?
2、在什么条件下购买的保险金额是正的?
3、该金额与财富水平x有关吗??
恳求各位的帮忙,帮我解答下,将不胜感激!!!!
Suppose the loss is L (with probability p). The individual chooses the level of insurance (w) to maximize his expected utility:
(1-p)*e-r(x-w) +p*e-r(x-L+w)
Solve the first order condition for w to obtain:
w=(1/2r)*[ln(1-p)-ln(p)+rL]
Then, all your three questions would be easy and clear.