Semi-open thread: blackmail

Stuart_Armstrong

My blackmail posts have generated some interesting discussion, so I'm just creating this one so that people can post examples of behaviours that they think are either clearly blackmail, or clearly not blackmail, or something in between.

Consider the following (inspired by a conversation with Xixidu):

Agent A and agent B come to the following agreement: agent A will make a car for agent B for £100. They sign a contract for this. But no contract can be totally exhaustive, so some details are left out. One detail left out is the colour of the car.

Why? Because there are only two colours available, black (which costs £1) and green (which costs £150). Agent B much prefers black to green, so didn't bother to include that in the contract: obviously agent A isn't going to use paint that costs £150 on a car he's selling for less than that!

But A suddenly announces that he will, after all, paint the car green. He credibly commits to painting the car green, at a massive loss - unless agent B gives him an extra £10.

Blackmail or not? And would it be different if the price of green was high, but not so extreme?

Blackmail. A wouldn't make the threat if A believed that B ignored such threats, and A would have no motive to paint the car green if B were a rock. Pricing of green makes no difference so long as the price is not negative.

2wedrifid13y

Yes. [...] No. (At least, only marginally.)

3TrE13y

(Please note that in the following, I'm using "blackmail" for all sorts of attempted coercion or extortion) I'd say this formulation of yours is very useful for drawing some boundaries around the word "blackmail". Namely, the cost to the blackmailer in case the threat fails should be somewhat less, but at least comparable than the cost to the blackmailee in case the threat succeeds, or the threat will be simply viewed as stupid (although you could, technically, still call it "blackmail"). Or rather, this assumes a probability of success of 0.5. If this probability (as judged by the blackmailer, and historically checkable) is different, the threat and costs imposed on both blackmailer and blackmailee also have to change accordingly. For example, whole governments are known to work on a no-blackmail-basis, as officially announced. For example, when hostages are taken, government officials (at least in my country) frequently announce that their country will not let themselves be blackmailed. So in order for a threat to succeed, according to my model the costs to the threatener must be very low (e.g. they have safe refugee or asylum in a third country, and don't have to fear retaliation in case the threat fails and they have to act on it) and the costs to the country or government (incremental over succumbing to the threat) very high (e.g. the leaking of diplomatically relevant documents which can seriously damage international relations). In your example from above, I'd argue that the threat (with $150 green paint) has a chance of succeeding if and only if: * (a) The customer has been successfully blackmailed many times before, and this is common knowledge and/or * (b) The customer really needs a black car because of some obscure reason, and only this car, only in black, will somehow give him huge profits. This is also common knowledge. The question is whether one can reason about why this is so, utilizing some form of TDT or -derivative.