This study empirically quantifies the efficiency of a real-world bargaining game with two-sided incomplete information. Myerson and Satterthwaite (1983) and Williams (1987) derived the theoretical ex-ante efficient frontier for bilateral trade under two-sided uncertainty and demonstrated that it falls short of ex-post efficiency, but little is known about how well bargaining performs in practice. Using about 265,000 sequences of a game of alternating-offer bargaining following an ascending auction in the wholesale used-car industry, this study estimates (or bounds) distributions of buyer and seller values and evaluates where realized bargaining outcomes lie relative to efficient outcomes. Results demonstrate that the ex-ante and ex-post efficient outcomes are close to one another, but that the real bargaining falls short of both, suggesting that the bargaining is indeed inefficient but that this inefficiency is not solely due to the information constraints highlighted in Myerson and Satterthwaite (1983). Quantitatively, findings indicate that over one-half of failed negotiations are cases where gains from trade exist, leading an efficiency loss of 12–23% of the available gains from trade.

中文翻译：

---

现实世界中的讨价还价效率：二手车批发拍卖的证据

这项研究从经验上量化了带有两面不完整信息的真实世界讨价还价游戏的效率。Myerson and Satterthwaite（1983）和Williams（1987）得出了在两面不确定性情况下双边贸易的事前有效前沿理论，并证明了其不足事前效率，但对议价在实践中的执行情况知之甚少。这项研究使用了批发二手车行业中不断上升的拍卖后的265,000个交替报价谈判的序列，该研究估算（或限定）了买卖双方价值的分布，并评估了实际议价结果相对于有效结果的位置。结果表明，事前和事后的有效结果彼此接近，但实际的讨价还价能力不足 这表明讨价还价的确是低效率的，但是这种低效率的原因不仅仅在于Myerson和Satterthwaite（1983）中强调的信息约束。从数量上看，调查结果表明，有超过一半的谈判失败是存在贸易收益的情况，导致效率损失为可利用的贸易收益的12％至23％。