In the past, enterprises pursue the maximization of profit and do not pay attention to the adverse impact on society and the environment. Nowadays, the ideological atmosphere that values environmental ecology and giving back to the society is gradually prevalent, which makes people pay attention to this issue. According to the "Taiwan Stock Exchange Corporation Rules Governing the Preparation and Filing of Sustainability Reports by TWSE Listed Companies", listed companies that comply with the requirements shall prepare a corporate social responsibility report every year in accordance with the GRI Standards issued by the Global Reporting Initiatives (GRI) and indicates whether each disclosed item in the report has been assured or guaranteed by a third party.
For enterprises, neither underinvestment nor overinvestment can bring the maximum benefit to the enterprise, and the agency cost caused by information asymmetry also affects the investment efficiency of the enterprise. Prior research has pointed out that the assurance of CSR reports can reduce the problem of information asymmetry and improve the information disclosure ranking. Some literatures also pointed out that increasing information disclosure makes private information more accessible, thus increasing information asymmetry, reducing stock liquidity, and increasing capital costs, in turn to reducing investment efficiency. The empirical results of this study found that the assurance of CSR reports has a significant negative impact on investment efficiency; but the CSR reports assured by two assurance providers has an insignificant negative impact on investment efficiency.
