Thanks for the link. I get that "Convicts eventually proven innocent" is most likely a lower bound (probably not too many guilty ones later exonerated?), but I figured I'd have to work from there to get a crude guess.

On one hand, even 10% isn't all that bad in an absolute sense- most of the deterrent is being had with not too much additional waste. On the other, that means that our trial and jury system is probably worse than I thought, if it's true that "most" people charged with a crime plead guilty.

I'll look up the statistics and report back in a couple days.