Some applications of Nash bargaining in the antitrust analysis of reverse payment settlements estimate the bargaining power parameter as the split of the surplus in the actual settlement with alleged reverse payments. This estimated parameter is then used as the bargaining power parameter in the but-for world where reverse payments are prohibited. We demonstrate that this approach is incorrect. Indeed, in the but-for world there could theoretically be an alternative “no payment” settlement where reverse payments are prohibited. However, the prohibition on reverse payments disproportionately affects the shape of the bargaining set in favor of the patent holder. With this asymmetry in the bargaining set, the estimated “bargaining power” in the actual world (with a settlement) no longer accurately reflects the split of the surplus that would have been agreed during the but-for negotiation with no payments. Moreover, we find that keeping the split of the surplus constant between the actual and but-for worlds is not innocuous because it overestimates the extent of alleged generic delay.

中文翻译：

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纳什讨价还价在制药业反向付款案例中的应用

Nash讨价还价在逆向付款清算的反托拉斯分析中的一些应用将讨价还价参数估计为实际清算中有所谓的反向付款的盈余的分配。然后，在禁止反向支付的“ but-for”世界中，此估计参数用作议价能力参数。我们证明这种方法是不正确的。的确，在“但是”世界中，在理论上可能存在替代的“不付款”结算方式，其中禁止反向付款。但是，禁止反向付款对专利持有人有利的谈判形式产生了不成比例的影响。由于谈判中的这种不对称，现实世界中（带有和解协议）的估计“议价能力”不再准确地反映了在无偿谈判的前提下商定的盈余的分配。此外，我们发现，使实际世界与对等世界之间的盈余保持恒定不变并不是无害的，因为它高估了所谓的一般性延误的程度。