I don't like many of the standard arguments against capital punishment. In particular, I'm tired of the argument "if you just put an innocent person in jail, they might be exonerated later. If you execute an innocent person, and they are exonerated later, it's too late."

Of course, I then point out that people can be exonerated in the time between being convicted and being executed (which can be quite long sometimes), and the response is generally that in the life sentence there's always some chance of being freed due to exoneration while in the capital punishment case, there's a segment of time where there's no chance of being freed.

My response is that a chance X of being freed due to exoneration when sentenced to life in prison is, for some Y, equivalent to having a chance Y of being freed due to exoneration before your execution and zero chance of being freed after being executed. Since there are values of X that are considered acceptable, there are values of Y that must be acceptable too and therefore this argument cannot be used as a basis for an absolutist anti-capital-punishment stance.

I have yet to have anyone understand my response (the few times I've tried it, anyway). But it seems to me that I've stumbled onto something equivalent to the Allais problem. People don't think of "chance X of being freed" and "chance Y of being freed before execution and no chance of being freed after execution" as statements that can ever be equivalent, because they really don't like the certain failure in the last example, even though the two may be mathematically equivalent.