DANIEL.DAVIES at flemings.com wrote:
> Sadly, I didn't mean anything so clever. Among finance/econ geeks, E is
> also the "expectation" operator. So E(0) in this context is "Expectation
> at time 0". Brad said that life expectancy at birth was the least worst
> measure. I objected that E(0) wasn't equal to E(0)(E(10)) "expectation at
> time 0 of expectation at time 10". Usually, this would be equal to E(0) -
> after all, there's something funny about expecting your expectation to
> change, which is where the reference to "law of iterated expectations" came
> in. But when you're talking about life expectancies, you can expect that
> if you survive until ten, then your expectation of your lifespan will
> change markedly. I suggested that you should be comparing expectancies on
> the basis of life expectancy at the most common age for people to die,
> which, frankly, sounds a lot less silly when you use five-shilling words
> like "modal"
>
> "I hope that's a bit clearer"
Thank you Daniel. I actually learned something today. And it doesn't look silly at all but quite fascinating to someone who had never heard of it before.
Carrol