中文摘要：

本文以1999～2007年装备制造业规模以上企业为样本，研究我国国有企业改制阶段进入退出对产业生产率的影响。研究发现：（1）装备制造业进入退出频繁，国有控股企业占比不断减少，非国有控股企业占比大幅增加，呈现出“国退民进”态势；（2）随着高生产率企业的进入和低生产率企业的退出，装备制造业生产率水平逐年提高，产业结构不断优化，国有控股和非国有控股企业生产率差距逐步缩小；（3）政府对国有企业存在“父爱主义”情结，政府更倾向于补贴在市场竞争中处于弱势、生产率低的国有控股小型企业；（4）装备制造业小型企业大量进入和退出，其进入退出容易，但生存不易。非国有控股小企业在竞争中存活源于较高的生产率，而国有控股小企业存活源于政府补贴。

英文摘要：

Using panel data on equipment manufacturing industry over the 1999 -2007 period, we investigate the effect of entry and exit on the productivity during state-owned enterprises stage. The results show that： （ 1 ） firms frequently enter in- to and exit from equipment manufacturing industries. The proportion of state-holding firms decline gradually, while non-state- owned holding firms increase substantially, which present a phenomenon of “country exit and private entry” ; （2） With the en- tering of high-productivity firms and exiting of low-productivity, productivity of the equipment manufacturing industry has grad- ually increased, and the industrial structure also continue to optimize, then the gap of productivity between state-holding and non-state-holding enterprises is narrowed; （3） Government＇s “paternalism” to state-owned firms is still existing. In other words, government is more inclined to provide subsidizes to state-holding firms whose productivity is low and which is vulnera- ble in the competition; （4） A large number of firms enter into and exit from equipment manufacturing industry. Their entry and exit is easy, but survival not. Non-state-owned holding firms survive because of their high productivity, whereas state- owned holding firms survive due to subsides.