Newcomb's Problem vs. One-Shot Prisoner's Dilemma

Let's say I'm about to engage in a one-shot PD with Jeffreyssai. I know that Jeffreyssai has participated in one-shot PDs with a variety of other agents, including humans, cats and dogs, paperclip maximizers from other universes, and Babyeaters, and that the outcomes have been:

• 87% D,D
• 12% C,C
• 1% C,D or D,C

In this scenario it seems obvious that I should cooperate with Jeffreyssai. Real life situations aren't likely to be this clear-cut but similar reasoning can still apply.

Edit: To make my point more explicit, all we need is common knowledge that we are both consistent one-boxers, with enough confidence to shift the expected utility of cooperation higher than defection. We don't need to exchange source code, we can use any credible signal that we one-box, such as pointing to evidence of past one-boxing.

With regard to source proof, the process you mention is only expensive if it must be performed every time for any two AIs. If you're already running on a piece of hardware with some kind of remote attestation capability then the cost could be significantly lower. Not useful for humans, though.

Oh, small internet. I went looking for a link to a system I ran across a few years ago called RPOW as a sample application of current technology along these lines, and found the author to be none other than Hal Finney! Is that you, Hal? My compliments on the very interesting project if so.

Are there cheaper solutions

If you have good reason to beleive the superintelligence is a sucessful extrapolation of the values of it's creators, simulate them (and their discussion partners) a few million times pondering appropriate subjects - PD, Newcolme's, and similar problems. That should give you a good idea, with much less computronium spent that a mutual simulation or rewriting pact with the other SI would cost.

Are there cheaper solutions

If you have good reason to beleive the superintelligence is a sucessful extrapolation of the values of it's creators, simulate them a few million times discussing problems of a similar nature - PD, Newcolme's, and similar problems. That should give you a good idea, with much less computronium spent that a mutual simulation or rewriting pact with the other SI would cost.

Meta-game the PD so that each player is allowed a peek at the answer before the answer is finalized and are given the option to stay or switch. If either player switches, repeat the process. Once both players stay, input their decisions and dole out rewards.

The scenario would look like this:

Player 1 chooses C
Player 2 chooses D

During the peek, Player 1 notices he will lose so he will switch to D.
During the next peek, both players are satisfied and stay at D.
Result: D, D

OR

Player 1 chooses C
Player 2 chooses C

During the peek, neither switch
Result: C, C

OR

Player 1 chooses C
Player 2 chooses C

During the peek, Player 2 switches to D
During the next peek, Player 1 switches to D
During the third peek, neither player switches
Result: D, D

The caveat with this is that it requires a trustworthy system of holding an answer and understanding the rules of how to fully submit them and allowing them to change their answer. Under such a system it is perfectly logical to choose Cooperate because there is no risk of losing to a Defector.

This directly answers your question of how players can "convince each other that Player1.C <=> Player2.C."

I do not understand how your example of an SI's claim on their source-code constitutes a Prisoner's Dilemma.

 tag I can use to force newlines to format as a line break?  Or do people just use the >?

A bit off-topic, but it seems to me that a lot of debate raging around Newcomb's problem can be well summarized by the following statement. If you believe yourself a rationalist and you witness a miracle, then you better update your whole, damn, world view to accommodate existence of miracles.