开发区与企业动态成长机制*--基于企业进入、退出和增长的研究

开发区的高速增长到底是源自寻求“政策租”所导致的短期“虚假繁荣”，还是通过集聚效应推动企业迅速成长而形成的长期表现？回答好这一问题，对于开发区政策的效果评价和进一步完善至关重要。然而，现有研究对此却语焉不详。文章在识别开发区企业的基础上，实证检验了开发区对企业进入、退出和成长的作用，以及开发区增长效应的可持续性，揭示了开发区影响地区经济增长的微观机制。研究发现：(1)开发区会吸引高效率企业进入，并降低开发区内企业的退出风险，从而使得开发区内净进入企业数目显著增加，这意味着开发区政策是吸引企业入驻并加强集聚经济的重要因素；(2)开发区显著提高了企业的就业增长、生产率增长和销售增长，这表明开发区政策和集聚经济的增长效应十分明显；(3)企业“入驻”开发区初期，“政策租”带来了短期的快速增长，而开发区内自我加强的集聚经济对企业成长具有长期的促进作用，这说明开发区的增长效应具有可持续性。文章肯定了开发区实践对企业动态成长的长期积极影响，这不仅为开发区政策绩效的评估提供了更为全面的认识，而且也为开发区的进一步发展和完善提供了重要启示。

Special Economic Development Zones and Firm Dynamic Growth:Research Based on Firm Entry,Exit and Growth

Does the rapid growth of development zones stem from short-term false prosperity resulting from policy rents or long-term performance formed from rapid firm growth through agglomeration effect in the end? The solution to this question is of great importance to the evaluation of the effectiveness of development zone policy and further perfection.However,existing research is vague about this question.By identifying firms from development zones,this paper empirically tests the role of development zones in firm entry,exit and growth as well as the sustainability of the growth effect of development zones.Then it reveals the micro mechanisms of the effect of development zones on regional economic growth.It arrives at the conclusions as follows:firstly,development zones at-tract effective firms to enter,and reduce the exit risks of firms in development zones, thereby leading to the significant increase in the net number of firms entering development zones and meaning that favorable policies are really the important factors attracting firms to locate in development zones and strengthening the agglomeration economy;secondly, development zones significantly improve firm growth rates of employment,productivity and sales,that is to say,development zone policies and agglomeration economy can bring a rapid growth for firms;thirdly,policy rents bring short-term rapid growth and self en-hanced agglomeration economy in development zones plays a long-term promotion role in firm growth,showing the sustainability of growth effect of development zones.This paper affirms the long-term positive effect of development zone practices on firm dynamic growth.It not only provides more comprehensive understanding for the performance evalu-ation of development zone policies,but also offers important enlightenment for further growth and perfection of development zones.