Pavitra comments on Open Thread, August 2010-- part 2 - Less Wrong

3 Post author: NancyLebovitz 09 August 2010 11:18PM

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Comment author: Pavitra 27 August 2010 08:51:16PM -1 points [-]

No, see, that's different.

If you're dealing with a blackmailer that might be able to carry out their threats, then you investigate whether they can or not. The blackmailer themselves might assist you with this, since it's in their interest to show that their threat is credible.

Allow me to demonstrate: Give $100 to the EFF or I'll blow up the sun. Do you now assign a higher expected-value utility to giving $100 to the EFF, or to giving the same $100 instead to SIAI? If I blew up the moon as a warning shot, would that change your mind?

Comment author: [deleted] 27 August 2010 09:06:44PM 0 points [-]

If you're dealing with a blackmailer that might be able to carry out their threats, then you investigate whether they can or not. The blackmailer themselves might assist you with this, since it's in their interest to show that their threat is credible.

The result of such an investigation might raise or lower P(threat can be carried out). This doesn't change the shape of the question: can a blackmailer issue a threat with P(threat can be carried out) x U(threat is carried out) > H, for all H? Can it do so at cost to itself that is bounded independent of H?

Allow me to demonstrate: Give $100 to the EFF or I'll blow up the sun.

I refuse. According to economists, I have just revealed a preference:

P(Pavitra can blow up the sun) x U(Sun) < U(100$)

If I blew up the moon as a warning shot, would that change your mind?

Yes. Now I have revealed

P(Pavitra can blow up the sun | Pavitra has blown up the moon) x U(Sun) > U(100$)

Comment author: Pavitra 27 August 2010 09:09:39PM *  1 point [-]

I have just revealed a preference:

P(Pavitra can blow up the sun) x U(Sun) < U(100$)

My point is that U($100) is partially dependent on P(Mallory can blow up the sun) x U(Sun), for all values of Mallory and Sun such that Mallory is demanding $100 not to blow up the sun. If P(M_1 can heliocide) is large enough to matter, there's a very good chance that P(M_2 can heliocide) is too. Credible threats do not occur in a vacuum.

Comment author: [deleted] 27 August 2010 09:13:46PM 0 points [-]

I don't understand your points, can you expand them?

In my inequalities, P and U denoted my subjective probabilities and utilities, in case that wasn't clear.

Comment author: Pavitra 27 August 2010 09:33:16PM 0 points [-]

The fact that probability and utility are subjective was perfectly clear to me.

I don't know what else to say except to reiterate my original point, which I don't feel you're addressing:

Consider the proposition that, at some point in my life, someone will try to Pascal's-mug me and actually back their threats up. In this case, I would still expect to receive a much larger number of false threats over the course of my lifetime. If I hand over all my money to the first mugger without proper verification, I won't be able to pay up when the real threat comes around.

Comment author: [deleted] 27 August 2010 10:18:28PM 1 point [-]

It's not even clear to me that you disagree with me. I am proposing a formulation (not a solution!) of Pascal's mugging problem: if a mugger can issue threats of arbitrarily high expected disutility, then a priors-and-utilities AI is boned. (A little more precisely: then the mugger can extract an arbitrarily large amount of utils from the P-and-U AI.) Are you saying that this statement is false, or just that it leaves out an essential aspect of Pascal's mugging? Or something else?

Comment author: Pavitra 27 August 2010 11:03:54PM -2 points [-]

I'm saying that this statement is false. The mugger needs also to somehow persuade the AI of the nonexistence of other muggers of similar credibility.

In the real world, muggers usually accomplish this by raising their own credibility beyond the "omg i can blow up the sun" level, such as by brandishing a weapon.

Comment author: [deleted] 27 August 2010 11:22:03PM *  0 points [-]

OK let me be a little more careful. The expected disutility the AI associates to a threat is

EU(threat) = P(threat will be carried out) x U(threat will be carried out) + P(threat will not be carried out) x U(threat will not be carried out)

I think that the existence of other muggers with bigger weapons, or just of other dangers and opportunities generally, is accounted for in the second summand.

Now does the formulation look OK to you?

Comment author: Pavitra 28 August 2010 01:29:46AM *  -2 points [-]

That formulation seems to fail to distinguish (ransom paid)&(threat not carried out) from (ransom not paid)&(threat not carried out).

There are two courses of actions being considered: pay ransom or don't pay ransom.

EU(pay ransom) = P(no later real threat) * U(sun safe) + P(later real threat) * U(sun explodes)

EU(don't pay ransom) = P(threat fake) * ( P(no later real threat) + P(later real threat) * P(later real threat correctly identified as real | later real threat) ) * U(sun safe) + ( P(threat real) + P(threat fake) * P(later real threat) * P(later real threat incorrectly identified as fake | later real threat) ) * U(sun explodes)

That's completely unreadable. I need symbolic abbreviations.

R=EU(pay ransom); r=EU(don't pay ransom)

S=U(sun safe); s=U(sun explodes)

T=P(threat real); t=P(threat fake)

L=P(later real threat); M=P(no later real threat)

i=P(later real threat correctly identified as real | later real threat)

j=P(later real threat incorrectly identified as fake | later real threat)

Then:

R = M*S + L*s

r = t*(M + L*i)*S + (T + t*L*j)*s

(p.s.: We really need a preview feature.)

Comment author: [deleted] 28 August 2010 02:38:46AM *  0 points [-]

Why so much focus on future threats to the sun? Are you going to argue, by analogy with the prisoner's dilemma, that the iterated Pascal's mugging is easier to solve than the one-shot Pascal's mugging?

That formulation seems to fail to distinguish (ransom paid)&(threat not carried out) from (ransom not paid)&(threat not carried out).

I thought that, either by definition or as a simplifying assumption, EU(ransom paid & threat not carried out) = current utility - size of ransom, and that EU(ransom not paid & threat not carried out) = current utility.