Effects of Managers’ over confidence on Voluntarily Information Disclosure and Social Responsibility of Companies Listed in Tehran Stock Exchange

In this research, 126 companies as a sample of listed companies in Tehran Stock Exchange during the period of 2009-2010 were surveyed to investigate the effect of managers’ over confidence bias(as one of the behavioral biases) on two variables including the voluntary disclosure of information and social responsibility. The results of using the random effects model for both models showed that the sign of all the coefficients of the model variables were in agreement with the expected theoretical basis and all the estimated coefficients were statistically significant. R-squared of the voluntary disclosure model was 99% and in the social responsibility model 93%, which shows the good explanatory power of the patterns. Thus, it can be stated that there is a meaningful relationship between the more over confidence of managers and the amount of disclosure of information voluntarily and social responsibility.