地方政府债务为何持续扩张——基于撤县设区的准自然实验分析

Why Local Government Debts Are Lasting Enlargement?Evidence Based on City-County Merger

地方政府债务规模持续扩大是中国宏观杠杆率居高不下的症结所在。撤县设区引发的城市基础设施建设是否推动了地方政府债务的过快增长呢?本文以撤县设区作为准自然实验,利用2006—2017年全国280个地级市面板数据,采用双重差分法进行实证分析。研究发现撤县设区显著提高了城投债的发行规模与发行概率。进一步的机制分析表明,撤县设区会通过土地出让收入效应与地方政府竞争效应两个渠道推动债务增长。其中,土地出让收入效应的作用机制在于撤县设区可增加地级市政府可支配的土地资源,提高其偿债预期,推动地级市政府扩大地方政府债务规模;地方政府竞争效应的作用机制在于撤县设区将加剧地级市政府间竞争,从而扩大基础设施建设与财政收入规模,进而加剧地方政府债务的增长。对于不同地区、不同组合类型的城市,撤县设区对地方政府债务具有异质性影响:相较于中部地区,东西部城市的债务规模扩张更严重,强县设区的债务增长效应大于弱县设区。本文的研究表明,当前亟需理性、合理地推动撤县设区,盲目撤并可能会导致地方政府债务积累,从而加剧债务风险,不利于城市经济健康发展。

In recent years,the lasting enlargement of local government debts is the most important sticking point of China?s high macro-leverage. City-county Merger is one of the effective tools for central government to adjust the local governments’ administrative boundaries. Using this event as a quasi-natural experiment and exploiting the staggered Difference-in-Differences method,we examine the impact of City-county Merger on the expansion of local government debts,based on the prefecture-level panel data from 2006 to 2017. The study finds that after the separation of the effects of other factors on the expansion of local government debts,this policy significantly stimulated the expansion of debts. The result is still valid after a series of robustness tests. In addition,this paper discusses the underlying mechanism of this effect. The reason is that reforms increase the land resources of reformed prefecture governments and intensify government competition to some extent to issue more municipal investment bonds. The former mechanism is that reforms can increase the land resources and expectation of reformed prefecture governments,and then influence the issuance of debts. The latter mechanism is that the reforms will intensify prefecture government competition to some extent,thus increase the issuance of debts in order to expand the size of infrastructure construction and fiscal revenue. Moreover,we find that the promotion effect varies among different types of City-county Merger and regions. The paper suggests that because the reform may increase local government debts too fast and result in detrimental effect on urban economy,the government should be aware of these adverse effects of this policy before considering City-county Merger.