# Math Help - Survival models : complete expectation of a life

1. ## Survival models : complete expectation of a life

Why is $e_0^o \neq 21 + e_{21}^o$ ?
$e_x^o$ is complete expectation of life at age $x$
Using ELT15 (males) mortality table

$e_0^o = 73.413$ and $e_{21}^o = 53.497$

but I'm unable to conclude on that equation.

2. ## Re: Survival models : complete expectation of a life

Because the life aged 0 is not guaranteed to reach age 21.
if you dont see the significance of this, consider what your intuition says about $e_{75}^0$ .

PS: this is not a specialist actuarial forum, try defining your terms in your posts.