School of Engineering and Computer Science, Victoria University of Wellington, Wellington, New Zealand.
School of Mathematics and Statistics, Victoria University of Wellington, Wellington, New Zealand.
Proc Biol Sci. 2022 Aug 10;289(1980):20220723. doi: 10.1098/rspb.2022.0723.
Strangers routinely cooperate and exchange goods without any knowledge of one another in one-off encounters without recourse to a third party, an interaction that is fundamental to most human societies. However, this act of reciprocal exchange entails the risk of the other agent defecting with both goods. We examine the choreography for safe exchange between strangers, and identify the minimum requirement, which is a shared hold, either of an object, or the other party; we show that competing agents will settle on exchange as a local optimum in the space of payoffs. Truly safe exchanges are rarely seen in practice, even though unsafe exchange could mean that risk-averse agents might avoid such interactions. We show that an 'implicit' hold, whereby an actor believes that they could establish a hold if the other agent looked to be defecting, is sufficient to enable the simple swaps that are the hallmark of human interactions and presumably provide an acceptable trade-off between risk and convenience. We explicitly consider the particular case of purchasing, where money is one of the goods.
陌生人在一次性相遇中，在彼此不了解的情况下，经常进行合作和商品交换，而无需诉诸第三方，这种互动是大多数人类社会的基础。然而，这种互惠交换的行为伴随着对方带着货物违约的风险。我们研究了陌生人之间安全交换的舞蹈编排，并确定了最低要求，即共同持有，无论是物品还是对方；我们表明，竞争的代理人将在收益空间中确定交换作为局部最优。在实践中很少看到真正安全的交换，尽管不安全的交换可能意味着风险厌恶的代理人可能会避免这种互动。我们表明，一种“隐含”的持有，即如果另一个代理看起来要违约，一个演员相信他们可以建立一个持有，足以使简单的交换成为人类互动的标志，大概在风险和便利之间提供了可接受的权衡。我们明确考虑了购买的特殊情况，在这种情况下，金钱是一种商品。
