Abstract: Local government implicit debt is mainly borrowed by Local Government Financing Vehicle（LGFV） Urban construction investment companies in cities are LGFV Focusing on the urban construction investment companies（UCIC） as the main body of debt borrowing and exploring the economic impact of urban construction investment companies on listed companies are of great significance to prevent and resolve the risk of local government implicit debt 
Based on financial data and bond issuance data of UCIC from 2014 to 2020，we use the staggered differenceindifferences（DID） model to examine the impact of urban construction investment companies equity investment in listed companies on the credit risk of urban construction investment bonds We find that shareholding in listed companies reduces the credit risk of urban construction investment bonds，which is still valid after a series of robustness tests
We then analyze the mechanisms We find that equity investment in listed companies can help the UCIC reduce the credit risk of urban construction investment bonds by improving their own business performance and increasing government support Equity investment of UCIC in listed companies cant reduce the credit risk of urban construction investment bonds by alleviating their own financing constraints
The study of heterogeneity finds that the credit risk of urban construction investment bonds decreases more significantly after UCIC takes shares in listed companies in areas with low per capita GDP and areas with weak financial pressure In cities with low marketization levels，the credit risk of urban construction investment bonds is significantly reduced after UCIC take shares in listed companies The incident of taking shares in listed companies has significantly reduced the credit risk of urban construction investment bonds issued by UCIC issuing high credit rating bonds and with weak profitability
The conclusion of this study shows that the shareholding of UCIC in listed companies may become an important way to effectively resolve the risk of implicit debt of local governments We suggest to accelerate the transformation of LGFV to marketoriented investment and operation companies Meanwhile，the government financing functions of LGFV should be stripped away according to law to get rid of their dependences on local governments

Key words: local government implicit debt, urban construction investment companies, urban construction investment bonds, credit risk

摘要： 本文基于2014—2020年城投公司财务数据与城投债数据，采用交错双重差分模型考察了城投公司入股上市公司对城投债信用风险的影响。研究发现：入股上市公司降低了城投公司发行城投债的信用风险，且在进行了一系列稳健性检验后该结论依然成立。机制研究发现：城投公司入股上市公司后，通过提高自身经营绩效、增强政府支持降低了城投债信用风险。异质性分析发现：低经济发展水平、低财政收入以及低市场化水平地区的城投公司入股上市公司对其城投债信用风险的缓释作用更强；城投债信用评级较高以及盈利能力较弱的城投公司入股上市公司后发行的城投债信用风险更低。这说明城投公司入股上市公司可能成为有效化解地方政府隐性债务风险的重要途径。

关键词: 地方政府隐性债务, 城投公司, 城投债, 信用风险