混合所有制公司中的国有股权——论国有股减持的理论基础

State Ownership of Mixed Ownership Firms:Theoretical Foundation of Reducing Government Shareholding Fraction

本文通过回答以下问题来建立国有股减持的理论基础 :国有股权在混合所有制公司中的作用是什么 ,以及国有股权比重应该如何调整。以截止 1 998年底的中国上市公司为样本 ,我们首次考虑了股权结构内生性可能 ,以及公司上市时 ,政府在决定国有股权比重过程中面临的逆向选择问题 ,即在上市前业绩较差的公司 ,由于其较差的初始业绩导致较低的可流通股发行额度 ,政府不得不保留更多的国有股 ,从而表现为上市前业绩越差 ,上市时国有股权比重越高的反向关系。给定中国上市公司面临的独特制度环境 ,我们有以下发现 :( 1 )公司上市后 ,国有股股东有助于改善公司业绩 ;( 2 )公司上市时 ,政府在决定国有股权比重过程中确实存在着逆向选择问题 ;( 3 )公司上市后 ,国有股权比重内生决定于公司利润最大化过程 ,上市后的业绩越差 ,国有股比例越低。分析结果的政策含义在于 :政府减持国有股不能“一刀切” ,而应以公司业绩为依据 ,首先在上市后业绩较差的公司进行减持。

In order to build up the theoretical foundation of reducing state shareholding fraction,we ask the following two questions:What is the role of state ownership of mixed ownership firms in transition economies?Should state ownership be quickly reduced or kept at certain level in these frims?Utilizing a unique data set of mixed ownership firms listed in China stock exchanges (until 1998),and controlling for both the endogeneity of ownership structure and the downward self-selection bias of government during initial public offering (IPO) process,i.e.,government as the sole type of owner before IPO has to keep larger stakes at the beginning of after-IPO period in poor-performing firms,simultaneous equations analysis shows:(1)State owners have significantly improved firm performance after IPO.(2) Downward self-selection bias of government during IPO process does exist.(3)The worse firm performance after IPO,the smaller state ownership fraction,which confirms our endogenous state ownership assumption.The policy implication is that government should reduce its shareholding fraction according to after-IPO firm performance instead of reducing it in all firms.