Variable	Variable name	Variable symbols	Variable definition or calculation method
Dependent variable	Cash holdings	CASH1	(Cash + cash equivalents)/total assets, with reference to Opler et al. (1999)
Dependent variable	Cash holdings	CASH2	(Cash + cash equivalents)/net assets, net assets = total assets − (cash + cash equivalents), referring to Haushalter et al. (2007)
Explanatory variable	Equity concentration	ONESHARE	The shareholding ratio of the first largest shareholder, whose square item is recorded as ONESHARESQ
	Shares held by other major shareholders	OTHERSHARE	Sum of shareholding ratio of the second to tenth largest shareholders
	Management shareholding	MSHARE	The shareholding ratio of the managers, including the directors, supervisors and senior management of the company, whose square item is recorded as MSHARESQ
	Proportion of state-owned shares	GSHARE	Proportion of state-owned shares
	Board size	BSIZE	Total number of board members (excluding honorary directors)
	Proportion of independent directors	IND	Number of independent directors/total number of directors
	Two jobs in one	DUAL	Dummy variable, the chairman and general manager of the two positions in one, take 1; otherwise, take 0
	Quality of internal control information disclosure	ICDI	Internal control information disclosure quality index, based on entropy model measurement
Control variable	Company size	LNSIZE	Logarithm of total assets
	Debt structure	DMS	Total current liabilities/total liabilities
	Asset liability ratio	LEV	Total debt/total assets
	Bank debt ratio	BANKDEBT	(Long term loan + short term loan)/total liabilities
	Net working capital ratio	NWC	(Current assets − cash equivalents − current liabilities)/total assets
	Dividend policy	DIV	Dummy variable, when the company pays cash dividends, take 1; otherwise, take 0
	Investment opportunity	MB	Market value of the company/book value of the company’s assets
	Nature of property rights	STATE	Dummy variable, 1 for state-owned enterprises and 0 for non-state-owned enterprises