I'm not aware of a satisfactory treatment of blackmail (in the context of reflective decision theory). The main problem appears to be that it's not clear what "blackmail" is, exactly, how to formally distinguish blackmail from trade.
I think blackmail can be taken as a form of threat. To use Schelling's definition (Strategy of Conflict), a threat has the property that after the person being threatened fails to perform the specified action, the threatener does not want to carry out the threat any more. In other words, the threatener has a credibility problem: he has to convince the target of the threat that he will carry it out once he desires not to. This requires some form of pre-commitment, or an iterated game, or a successful bluff, or something along those lines.
What do you see as the distinguishing difference between blackmail and a threat? (I assume that blackmail is a subset of threats, but I suppose that might not be universally agreed.)
From the last thread:
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