O que nos revela o jogo do ultimato

O jogo do ultimato é interessante.
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Um tipo recebe 10€ com uma condição, tem de os dividir com um desconhecido. Contudo, o tipo e o desconhecido só podem ficar com o dinheiro se o desconhecido aceitar a divisão.
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1.Por exemplo, o tipo pode propor: fico com 9,5€ e dou-te 0,5€.
Se o desconhecido rejeitar a proposta não há segunda oportunidade e ambos perdem os 10€.
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2.Por exemplo, o tipo pode propor: fico com 5€ e dou-te 5€.
Se o desconhecido aceitar a proposta ambos ficam com os 10€.
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Quando o desconhecido rejeita a proposta acontece algo interessante: ele opta por perder tudo em vez de perder menos!!!

"The vetoing responder is the game’s starkest challenge to economic theory. “It’s the resentment, the willingness to punish at cost, that is the whole thing,” Kahneman explained. The player who vetoes is rejecting logic no less than “free money” and making an economic decision on the basis of emotion. And it wasn’t just an occasional subject who acted contrary to the theory; practically everyone did.
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The ultimatum game is claimed to be one of the most frequently performed of all human experiments today. ...
Yet the main reason for its enduring popularity is the belief that the game tells us much about the psychology of prices and bargaining.
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“money alone does not rule the world” and that “simple games can be very complex.” Kahneman views the game as a milestone in establishing the importance of psychology in even simple economic decisions. “Something special had to happen for economists to pay attention,” he explained. “The ultimatum game had that feature.” One reason economists paid attention is the evident parallels to price setting. The $10 can represent the potential profit (“surplus”) on a sale. The person splitting the money is a “seller,” and the responder is a potential “buyer.” The seller may choose to keep all the profit for himself (set a high price) . . . or surrender all the profit to the seller (“sell at cost”) . . . or share the profit with the buyer. The buyer decides whether to accept the price or reject it as too high.
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The ultimatum game presents, in concentrated form, the truly difficult part of negotiation. Where one or more hard-line bargainers are involved, there must come a moment of truth in which feints, bluffs, and built-in bargaining room are cast aside, leaving only an ultimatum. What do you do then—allow yourself to be exploited, or walk away, leaving money on the table?"

O que diz a teoria económica do mainstream?
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Que os decisores são racionais?
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Pois!
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E ainda bem que não o são, isso é o que permite a concorrência imperfeita e abre espaço para os Davids deste mundo.
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Trecho retirado de "Priceless The Myth of Fair Value (and How to Take Advantage of It)" de William Poundstone.