Social governance, financial regulation, and corporate investment efficiency

• Social governance levels can enhance corporate investment efficiency. • Financial regulation can improve corporate investment efficiency. • Financial regulation impacts investment efficiency differently in SOEs and PEs. • Financial regulation's effect on investment efficiency has a threshold. This article selects data from publicly listed companies between 2011 and 2022 as a sample to explore the impact of social governance levels and financial regulation on corporate investment efficiency. Empirical results show that social governance levels can enhance corporate investment efficiency; financial regulation can improve corporate investment efficiency; there is heterogeneity in the impact of financial regulation on the investment efficiency of state-owned enterprises and private enterprises; and the effect of financial regulation on corporate investment efficiency exhibits a threshold effect, which varies with changes in the company's debt-to-asset ratio.