双边不对称信息下叫价显示质量机制研究

Asking prices as signals of quality under bilateral asymmetric information

资产交易前初始叫价(挂牌价)的确定一直是经济学家感兴趣的问题.现有研究认为该初始叫价反映了卖家的私人价值(如保留价格或生产成本),较少讨论其关于共同价值(如资产质量)的信号传递机制.本文在买卖双方存在双边不对称信息背景下,讨论初始叫价显示资产质量的可能性.研究表明:给定交易机会随质量上升而减少的市场条件,改变叫价对卖家存在相反的两种效应——价格效应和交易效应;低质量资产卖家的交易效应对于价格效应的边际替代率更高,使得该博弈的单交性条件成立;给定边界条件满足,博弈存在分离均衡;低质量卖家有动机以低价格向潜在买家显示质量水平,对高叫价待售资产的质量预期更高具有合理性;分离均衡下所有有效交易均能达成,克服了不对称信息下的市场失灵.

The issue of the asking price （AP） before trading has received much attention from economists.Most of the existing literature argues that AP can be used as a signal of the seller＇s reservation price or production cost,which is the private value of the seller.Little attention is paid to the relationship between the AP and the quality of an asset,which is a common value of the seller.We examine the signaling mechanism of the AP under bilateral asymmetric information.We find that,given that the trade opportunity shrinks with increasing quality,there are two contrasting effects with the change of the AP：the price effect and the trade effect.The marginal rate of substitution between the trade effect and the price effect is higher for the seller with a lower quality asset.This means that the single-crossing condition is satisfied in this bilateral asymmetric information game.Given the boundary condition is satisfied,there is a unique separating equilibrium.A seller with a lower quality has an incentive to signal the quality with a lower AP,and it is reasonable to expect a higher quality from assets with a higher AP.All possible trades will be accomplished in this unique separating equilibrium despite the informational asymmetry.