There are several aspects of data markets that distinguish them from a typical commodity market: asymmetric information, the non-rivalrous nature of data, and informational externalities. Formally, this gives rise to a new class of games which we call multiple-principal, multiple-agent problem with non-rivalrous goods. Under the assumption that the principal's payoff is quasilinear in the payments given to agents, we show that there is a fundamental degeneracy in the market of non-rivalrous goods. This multiplicity of equilibria also affects common refinements of equilibrium definitions intended to uniquely select an equilibrium: both variational equilibria and normalized equilibria will be non-unique in general. This implies that most existing equilibrium concepts cannot provide predictions on the outcomes of data markets emerging today. The results support the idea that modifications to payment contracts themselves are unlikely to yield a unique equilibrium, and either changes to the models of study or new equilibrium concepts will be required to determine unique equilibria in settings with multiple principals and a non-rivalrous good.

翻译：数据市场在几个方面区别于典型商品市场：信息不对称、数据的非竞争性以及信息外部性。从形式上看，这催生了一类新的博弈问题，我们称之为具有非竞争性商品的多委托人-多代理人问题。在委托人效用函数关于代理人支付呈拟线性的假设下，我们证明了非竞争性商品市场存在根本性的简并性。这种多重均衡现象同样影响了旨在唯一选择均衡的常用均衡定义精炼：变分均衡与归一化均衡通常也会出现非唯一性。这意味着现有的大多数均衡概念无法对当今新兴数据市场的均衡结果提供预测。研究结果表明，仅修改支付合同本身难以实现均衡的唯一性，要确定多委托人且存在非竞争性商品环境中的唯一均衡，要么需要改变研究模型，要么需要引入新的均衡概念。