A price on your head  

Slate has a cute piece by Steven E. Landsburg about the dollar value we typically place on an individual life. He explains:

So, how do we find out how much a life is really worth? One of the best ways is to measure how much extra you have to pay someone to take a dangerous job. If lion tamers and elephant tamers have comparable skills and comparable working conditions, but lion tamers earn $20,000 a year more than elephant tamers, it's probably because that's what it takes to compensate someone for the risk of being eaten by a lion. And if that risk amounts to, say, an extra half-percent probability of dying on the job, then you figure that the value of a life must be $20,000 per half-percent, or $40,000 per percentage point, or $4 million.

So, once you carry out that experiment, how much does a typical life turn out to be worth? Professors Dora Costa of MIT and Matthew Kahn of Tufts point out that it depends on exactly when you asked the question. As incomes have risen, so has the value of life. The increase is more than proportional: A 10 percent rise in income is generally associated with about a 15 percent rise in the value of a life. Between 1940 and 1980, according to Costa and Kahn, the value of a life increased from about $1 million 1990 dollars to between $4 million and $5 million 1990 dollars.

UPDATE: I didn't catch this before, but Landsburg is the author of The Armchair Economist, which is for the most part equally cute. He does have a tendency to oversimplify things - an old English prof of mine would have called him "reductive" - and it doesn't serve him very well where non-economic factors are at play... but that's a tendency almost all economists seem to have.