S. Jabbarzadeh Kangarlouei - Department of Accounting, Science and Research Branch, Islamic Azad University, West Azarbyjan, Iran.
B. Kavasi - Department of Accounting, Science and Research Branch, Islamic Azad University, West Azarbyjan, Iran.
M. Motavassel - Department of Accounting, Science and Research Branch, Islamic Azad University, West Azarbyjan, Iran.

The aim of this study is to investigate the effects of outside board on rm value in Tehran Stock Exchange (TSE) from the perspective of information transaction costs. To do so, a sample of ۹۶ firms listed in TSE is selected to be studied during the period of ۲۰۰۳-۲۰۱۲. Tobin q ratio is used to measure rm's value and bid-ask spread for information transaction costs. In addition to these variables, four control variables are adapted namely rm's characteristic, age, size and duality. The results of the study show that there is not a signicant relationship between outside board and firm's value. Investigating the relationship between outside board and rm's value, the results indicate that only in food and non-metal industries, there is a negative relationship between outside board and firm's performance. Therefore, it can be concluded that not in all of industries outside board affects rm's value. Further, results do not prove the effects of outside board on information transaction cost. In addition, the results do not support that information transaction cost aect rm's value. Finally, the results also suggest that independence and presence of outside board of director member does not a effect firm's value in rms with lower information transaction cost.

Outside Board, Firm Value, Information Transaction Costs and Tehran Stock Exchange