Re: Force of Mortality as Conditional p.d.f

Michael Callahan ( (no email) )
Wed, 28 Jul 1999 13:30:28 -0400

The force of mortality is a conditional pdf: force of mortality =
f(x)/(1-F(x)), where f(x) is the pdf and F(x) is the df. If you integrate
from zero to infinity on both the top and bottom of the equation you get 1/0
(or something very close to zero) making the integral of the force of
mortality from zero to infinity equal to infinity. Refer to 3.2.12 on page
55 and table 3.2.1 on page 57.

-----Original Message-----
From: Medina, Hernan <HMedina@iso.com>
To: 'studygroup4A@lists.casact.org' <studygroup4A@lists.casact.org>
Date: Wednesday, July 28, 1999 9:09 AM
Subject: Force of Mortality as Conditional p.d.f

>Page 55, section 3.2.4, seems to indicate that the force of
>mortality is the conditional p.d.f. of X at exact age x,
>given survival to age x. However, the integral from zero
>to infinity of the force of mortality is infinity instead
>of 1. How do you explain this?
>