Yudkowsky has written about The Ultimatum Game. It has been referenced here 1 2 as well.
When somebody offers you a 7:5 split, instead of the 6:6 split that would be fair, you should accept their offer with slightly less than 6/7 probability. Their expected value from offering you 7:5, in this case, is 7 * slightly less than 6/7, or slightly less than 6.
Sure, but it does not preclude it. Moreover, if the costs of the actions are not borne by the altruist (e.g. by defrauding customers, or extortion), I would not consider it altruism.
In this sense, altruism is a categorization tag placed on actions.
I do see how you might add a second, deontological definition ('a belief system held by altruists'), but I wouldn't. From the post, "Humane" or "Inner Goodness" seem more apt in exploring these ideas.
Broadly, he predicts AGI to be animalistic ("learning disabled toddler"), rather than a consequentialist laser beam, or simulator.
This concept is introduced in Book 1 as the solution to the Ultimatum Game, and describes fairness as Shapely value.
When somebody offers you a 7:5 split, instead of the 6:6 split that would be fair, you should accept their offer with slightly less than 6/7 probability. Their expected value from offering you 7:5, in this case, is 7 * slightly less than 6/7, or slightly less than 6.
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Once you've arrived at a notion of a 'fair price' in some one-time trading situation where the seller sets a price and the buyer decides whether to accept, the seller doesn't have an incentive to say the fair price is higher than that; the buyer will accept with a lower probability that cancels out some of the seller's expected gains from trade. [1]
Eliezer: What do you want the system to do?
Bob: I want the system to do what it thinks I should want it to do.
Eliezer: The Hidden Complexity of Wishes
Gwern has a fantastic overview of time-lock encryption methods.
A compute-hard real-time in-browser solution that doesn't rely on exotic encryption appears infeasible. (You'd need a GPU, and hours/days worth of compute for years of locking). For LW, perhaps threshold aggregate time-lock encryption would suffice (though vulnerable to collusion/bribery attacks, as noted by Gwern).
I agree with Quintin Pope, a public hash is simple and effective.
While merely anti-bacterial, Nano Silver Fluoride looks promising. (Metallic silver applied to teeth once a year to prevent cavities).