مجتبی عالی فامیان

The purpose of this paper is to investigate the role of managerial ability in information environment quality in the listed companies on the Tehran Stock Exchange (TSE). This research has focused on the quality of the information environment and has attempted to investigate the impact of management ability along with other variables affecting the information environment quality such as size, performance, accrual quality, etc. In this study, to measure the quality of a company's information environment "ratio of stock return volatility to market return volatility "  and to measure managerial ability The Demerjian et. al. (2012) model is used. The systematic elimination method was used for sampling 105 firms listed in Tehran Stock Exchange during the time range 2015 to 2021, and the model of panel data was applied to test hypotheses. Based on the research results while managerial ability can enhance the quality of a company's information environment, the size and growth rate of the company can also affect the information environment quality.

This study examines the relationship between stock liquidity and return predicta-bility of 116 publicly-traded firms in Tehran Stock Exchange (TSE). To this end, we constructed a dated-regular frequency of time series with total 40128 stock-firm observations. After calculating daily bid-ask spreads and stock returns, the observations were classified based on liquidity into three classes and the return predictability was investigated across different classes using a set of parametric tests. The results exhibit signs of return autocorrelation and non-independence over three liquidity groups. Our findings didn’t show a connection between stock liquidity and market efficiency. The Hurst exponent also revealed mean reversion of returns series across different liquidity classes. We conclude that stock liquidity doesn’t play a significant role in market efficiency and return predictability of stocks in TSE. In case of TSE as other emerging markets, due to the small num-ber of traders (the need for more trading activity) and low market making activi-ties, both the cost of trading increases and the reaction to stock price information is delayed, resulting in predictability of price /return.