股票指数调整、外部融资行为与公司杠杆率——基于中证500指数的断点回归分析

Abstract

Based on the regular adjustments of the CSI 500 Index, this paper employs fuzzy regression discontinuity design to examine the impact and transmission mechanisms of stock index adjustments on external financing behavior and corporate leverage ratios of Chinese listed companies, and tests the heterogeneity of external environment and firm characteristic factors. The findings show that after being included as index constituent stocks, firms' debt financing and equity financing both increase, but the increase in debt financing exceeds that in equity financing, leading to a rise in corporate leverage ratios. Inclusion as an index constituent stock mainly affects external financing behavior and corporate leverage ratios through improving internal governance and enhancing the external financing environment. The impact on leverage ratio is more pronounced for firms with high economic policy uncertainty, in bull markets, with fewer analyst coverage, non-state-owned enterprises, and high-growth firms. This paper confirms that stock index adjustments play an information transmission role, and should alleviate corporate financing constraints by improving information environment, enhancing corporate governance, and optimizing financing environment, thereby increasing external financing opportunities and adjusting corporate leverage ratios.