Abstract:
مطابق با ادبیات نوین تامین مالی ، تعارضات نمایندگی به عنوان یکی از عوامل تعیین کنندهی ساختار سرمایه ی شرکت ها محسوب می شود. هم چنـین ، تصمیمات تامین مالی ، به عنوان یکـی از تـصمیمات اسـتراتژیک در ادارهی شرکت ها، تحت تاثیر ساز و کارهای راهبری شرکتی قرار دارد. از این رو در پژوهش حاضر، عوامل موثر بر ساختار سرمایه از دیـدگاه تئـوری نماینـدگی مورد بررسی قرار گرفته است . برای این منظور، دادههای مـورد نیـاز از ١٠٦ شرکت پذیرفته شده در بورس اوراق بهادار تهران طی سـالهـای ١٣٨٣ الـی ١٣٨٧ جمع آوری شده است . نتایج حاصل از آزمون فرضیه هـای پـژوهش بـا استفاده از مدل رگرسیون داده های ترکیبی ، بیانگر آن است که ساز و کارهای راهبری شرکتی ، شامل تمرکز مالکیت ، درصد اعضای غیرموظف هیاتمدیره و استقلال هیاتمدیره، تاثیر معناداری بر اهرم دفتری و اهرم بازار شـرکت هـای مورد بررسی ندارند. لیکن ، بین هزینه های نمایندگی با اهـرم دفتـری و اهـرم بازار، رابطه ی معنادار و مثبت وجود دارد. هم چنین ، نتایج بیانگر آن است که نسبت بازده دارایی ها، سود پرداختی هر سهم و نسبت Q- تـوبین ، از عوامـل
Introduction: In accordance with modern financing literature، agency conflicts are considered as one of the determining factors of the capital structure of companies. In agency theory، increased use of liabilities in the capital structure of the company is introduced as one of the ways to reduce agency costs، as the increased use of liabilities in the capital structure of the company leads to decrease in conflicts of interest between managers and shareholders by reducing the need for financing through owner's equity. On the other hand، the results of several studies suggest that agency conflicts are considered as one of the determining factors of capital structure of the companies. Moreover، financing decisions، as one of the strategic decisions in managing companies، are influenced by the mechanism of corporate governance.
Given the above، it can be concluded that the decrease in agency conflicts is related to financing through liability and there is also a relationship between financing decisions and agency costs and the mechanism of corporate governance. Hence، in this study، the factors affecting the capital structure of companies accepted in Tehran Stock Exchange are examined from the viewpoint of agency theory. Financing decisions of companies are complex processes and current theories، at best، can only explain certain aspects of diversity and complexity of financing choices. From management point of view، capital structure decisions are not only determined by internal and external factors affecting risk and control، but also values، goals، priorities and demands of management are very important inputs for financing decisions; In particular، financing decisions of the company are influenced by management conflicting incentives and managers' incentives for opportunistic actions can be influenced by corporate governance. On the other hand، it is argued that effectiveness of corporate investing decisions and the way of enjoying and using company's assets by managers in order to have more sales is also a factor affecting capital structure. Moreover، the results of previous studies show that profitability and growth are of effective factors on capital structure.
Hypothesis: In order to achieve the objectives of this research، the following hypothesis are developed and tested:
1) There is a significant relationship between corporate governance and financial leverage.
1-1) There is a significant relationship between ownership concentration and financial leverage.
1-2) There is a significant relationship between the percentage of outside directors on the board and financial leverage.
1-3) There is a significant relationship between the duality roles of the CEO and chairman and financial leverage.
2) There is a significant relationship between agency costs and financial leverage.
2-1) There is a significant relationship between assets turnover ratio and financial leverage.
2-2) There is a significant relationship between the ratio of operating expense to sales and financial leverage.
3) There is a significant relationship between profitability and financial leverage.
3-1) There is a significant relationship between ROA and financial leverage.
3-2) There is a significant relationship between DPS and financial leverage.
4) There is a significant relationship between growth and financial leverage.
4-1) There is a significant relationship between Tobin’s Q ratio and financial leverage.
Methods: The variables being considered are: book leverage and market leverage as the dependent variables، ownership concentration، the percentage of outside directors on the board، duality roles of the CEO and chairman، assets turnover، the ratio of operating expense to sales، ROA، DPS and Tobin’s Q ratio; and the control variables are assets structure، size and age of the company. In this research، 106 accepted companies in Tehran Stock Exchange، within the period 1383 to 1387 are investigated. For statistical analysis and to test hypothesis، the panel data regression are used.
Results: In this study، the factors affecting the capital structure of companies accepted in Tehran Stock Exchange was examined from the viewpoint of agency theory. The results obtained from examining these theories show that ownership concentration doesn't have a meaningful relationship with book leverage، but it has a positive meaningful relationship with market leverage which is in accordance with the study of Cespedes et al. (2009) and Fosberg (2004) and contrary to the results of Theis and Casey (1999) study. Also، the results show that the percentage of outside directors on the board and the duality roles of the CEO and chairman، according to Hassan and Butt (2009) and UgIurlu (2000) do not have any meaningful relationship with book leverage and market leverage. Contrary to Theis and Casey (1999) results، DPS doesn't have a meaningful relation with book leverage and market leverage. On the other hand، in accordance with Firth et al. (2000)، natural logarithm of assets turnover ratio has a negative meaningful relation with book leverage and market leverage. There is a meaningful relationship between natural logarithm of the ratio of operating expense to sale and ROA and company's growth، and book leverage، but there is not any meaningful relation between these variables and market leverage. Reflecting on the obtained results، it can be understood that in both book leverage and market leverage، agency costs criteria are more than other variables.
Machine summary:
"نتایج حاصل از آزمون فرضیه هـای پـژوهش بـا استفاده از مدل رگرسیون دادههای ترکیبی ، بیانگر آن است که ساز و کارهای راهبری شرکتی ، شامل تمرکز مالکیت ، درصد اعضای غیرموظف هیاتمدیره و استقلال هیاتمدیره، تأثیر معناداری بر اهرم دفتری و اهرم بازار شـرکت هـای مورد بررسی ندارند.
نتایج پژوهش نمازی و حشمتی (١٣٨٦) بیانگر این بود که بین سودآوری، بازده سهام، کسری مالی و نسبت ارزش بازار به ارزش دفتری دارایی هـای شـرکت بـا سـاختار سـرمایه رابطه ی معناداری وجود دارد.
در پژوهش حاضر نیز، مطابق با ایبـور (٢٠٠٨) و سیسپادس و همکاران (٢٠٠٩)، از نسبت سود قبـل از بهـره و مالیـات بـه ارزش دفتری دارایی ها، به عنوان معیار سودآوری استفاده شده است : فرضیه ی ششم : «بین نسبت بازده دارایی ها و اهرم مالی رابطه ی معناداری وجود دارد.
در این پژوهش ، مطابق با جیاپورن٢٥ و گلیسن ٢٦ (٢٠٠٧)، از نسبت مجموع ارزش بازار حقوق صـاحبان سـهام و ارزش دفتـری بدهی های شرکت تقسیم بر ارزش دفتری کل دارایی ها (نسبت Q- توبین ) به عنوان معیاری از فرصت های رشد استفاده می شود: فرضیه ی هشتم : «بین نسبت Q- توبین و اهرم مالی رابطه ی معناداری وجود دارد.
نتایج حاصل از بررسی خود همبستگی جمـلات خطـا بـا اسـتفاده از آمـاره دوربـین واتسون نیز بیانگر وجود خودهمبستگی بین خطاهای مدل بود که برای رفع آن، متغیر اهـرم بازار دورهی گذشته وارد مدل شده است .
Journal of Property Investment & Finance, 17(1): 27-34."
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