ساختار دموکراسی و دیکتاتور‌مدار بنگاه‌های اقتصادی در رابطه با بازار غیررقابتی

In this study, the relationship between structure of democracy and dictatorship firms, structure of non-competitive market and abnormal returns is assessed. For this purpose, we evaluate relationship the main criteria of the democracy structure in research literature on Iran's financial market- institution investors- and product market competition with abnormal return. It uses data that extracted from information published by the Stock Exchange of Tehran and tax records for 78 firms listed in Tehran stock exchange, also using multivariate regression, named Carhart's four factor models (1997). The results indicate that there is a significant correlation between the structure of democracy - the percentage of institutional shareholders - and abnormal returns in a non-competitive market. In other words, in the non-competitive market, whatever the democratic structure of the firm is more desirable becomes greater efficiency.