Board Structure and CEO Characteristics as Determinants of Firm Performance: An Analysis on BIST 100 Firms

Today, the Upper Echelon and Power theories are widely used to explain firm performance. These theories relate the size of top management and the power of managers (especially the CEO) to firm performance. However, no research has been found in the Turkish literature examining how senior management structure and CEO power affect firm performance. The aim of the study was determined as "detection of the effect of the structure of the board of directors and the characteristics of the CEO on the financial performance of the companies". In the research, a data set was created by considering the tenure of CEOs (7 years and above) in companies traded in the Borsa Istanbul 100 Index. The research data set includes 16 companies covering the period between 2016-2022, and the variables were obtained from the Thomson Reuters Eikon database. The dependent variables of the research are ROA, ROE and Tobin's Q, and the independent variables are CEO age, CEO duality, number of CEO titles, board size and board independence. Data were analyzed by the panel data analysis method. According to the research findings, CEO duality Tobin's Q, CEO age has a negative effect on ROA. Board size and CEO age have a positive effect on ROE. The number of titles held by the CEO and the board of directors' independence does not significantly affect firm performance. Research findings are important in showing the effect of board structure and CEO characteristics on firm performance.