理想的保險額度-計算部分(ideal uninsured amount calculation)
x= 收費倍率 y=RRA z= 損害 w= 不保險額度 u= 事件發生率 效用函數 U(x,y,z,w,u)=( (1-w-(z-w)*u*x)^(1-y)-1)/(1-y)*u + ( (1 -(z-w)*u*x)^(1-y)-1)/(1-y)*(1-u) ∂U/∂w = ((1 - u) u x)/(1 - u x (-w + z))^y + (u (-1 + u x))/(1 - w - u x (-w + z))^y If u is small enough, ((1 - u) u x)/(1 - u x (-w + z))^y + (u (-1 + u x))/(1 - w - u x (-w + z))^y ≈ u*(x- 1/(1-w)^y) u*(x- 1/(1-w)^y) = 0 => w = 1-x^(-1/y)