【正文】 Zhang et al. 2007). Thus, we expect that when the monitoring capability of the AC is high, management have fewer incentives to disclose on ICS.Research MethodSample. We analyze the disclosure on ICS made by firms listed in four European financial markets: London, Paris, Frankfurt, and Milan. We opted for an international sample made of firms operating in different national contexts characterized by different levels of investors protection in order to verify if different disclosure behaviors are associated to different national contexts, thus making our results more robust as not dependent from specific governance contexts. ICSs are recognized by the codes of best practice adopted in these four countries as key governance mechanisms supporting directors in coping with the responsibilities they are charged with in matters of reliability of information, pliance with the law, and effectiveness and efficiency of operations.Our sample consists of the first 40 largest firms listed on the London, Paris, Frankfurt, and Milan markets, in terms of market capitalization at , belonging to the DowJonesSTOXX600. To be included in the sample, each firm had to be listed for the 3 years period of the study (years 2003 – 2005).Measurement of ICS Disclosure. The definition provided by the COSO (1992) and adopted by the cited codes of best practice sets internal control as a process, carried out at various organizational levels, aimed at providing reasonable certainty regarding the achievement of the objectives of efficiency and effectiveness of operating activities, reliability of accounting information, pliance with laws and regulations. In the light of this definition, an ICS is effective when provides adequate protection against risks that can。 Beasley et al 2000). Regarding the latter finding, as a matter of fact, AC members with audit and accounting expertise can more easily review internal auditing documents and interact with internal auditors (Raghunandan et al. 2001。Goyal and Park, 2002). Accordingly best practices in corporate governance remend to separate the role of the chairman from that of the CEO (OECD, 2004).As CEO duality weakens the monitoring role of the board, we expect that management will have higher incentives to voluntarily disclose information on ICS in case of CEO duality.The monitoring role played by board members is enhanced by the variety and deepness of their petences. The accounting expertise is relevant for board members not only in the evaluation of management performance (through internal and external reporting), but also in appreciating the impact of accounting procedures and accounting information systems on the reliability of reporting. Moreover, accounting experts on the board promote the improvement of the systems devoted to quality assurance of financial reporting and ICS (Krishnan, 2005).Therefore, we expect that the presence of accounting experts on the board increases its supervisory petences and lowers incentives for management to make disclosure on ICS.The audit mittee plays a decisive monitoring role. Findings from previous studies suggest that the establishment of an Audit Committees (AC) generally has positive influence on the quality of corporate financial reporting (Beasley, 1999。 Pearce and Zahra, 1992): the proportion of independent directors of the board is considered a proxy of the capability of the board to control managerial actions (Fernandez and Arrondo, 2005) thus supporting a positive association between the proportion of independent members of the board and effectiveness of their monitoring role. Therefore, we expect that the higher the presence of independent directors, the lower incentives for management to voluntarily disclose on ICS.It has been argued that concentration of the roles of CEO (decision management) and chairman (decision control) in one single individual (CEO duality) reduces the board’s effectiveness in performing its monitoring function (Fama and Jensen, 1983。 Fama and Jensen, 1983). Empirical evidences support this expectation. Rosenstein and Wyatt (1990) explain the positive stock price effects associated to the appointment of a new independent director in terms of positive reaction signals of the markets to the monitoring role played by the outsiders. A number of studies document a positive relationship between the proportion of independent directors on the board and firms’ performance (Baysinger and Butler, 1985。Fernandez and Arrondo, 2005。 Deumes and Knechel, 2008), thus reducing the agency conflicts inside the firm (Eng and Mak, 2003。 Barako et al. 2006).Alternatively said, the direct supervision performed by large shareholders reduces the need for alternative monitoring mechanisms. Consequently, we expect that incentives to disclose on ICS are higher when the ownership is diffused.Institutional investors also play a relevant supervisory role. While individual investors in public firms have little incentive to monitor management as they are exposed to private costs against which there are public benefits (Grossman and Hart, 1980), institutional investors have higher incentives to play an active monitoring role on the management because of their large voting power (Milgrom and Roberts, 1992). Moreover, institutional investors can access to management through privileged information channels, in order to get disclosure on the firm’s operations (Schadewitz and Blevins, 1998). Thus we expect that in presence of institutional investors, management have lower incentives to disclose on ICS.The last proxy for the supervisory role of the ownership structure is the managerial ownership. It is generally accepted that management’s stock ownership contributes to the alignment of managerial and shareholders’ interests (Jensen and Meckling, 1976。 Leone, 2007), only few studies focused on the specific characteristics of ICS disclosure.Bronson et al. (2006) examine firm characteristics associated to disclosure on ICS be