پوشش رسانه‌ای مدیرعامل و همزمانی قیمت سهام: سیستم معادلات همزمان

بخش مهمی از پژوهش‌های بازار سرمایه به قیمت سهام وآگاهی‌بخشی آن به ویژه درباره اطلاعات خاص شرکت‌ها مربوط می‌شود. بر همین اساس، مفهوم همزمانی قیمت سهام و عوامل موثر بر آن که بیانگر قسمتی از آگاهی‌بخشی قیمت سهام است، هدف پژوهش‌های زیادی قرار گرفته است. در تبیین این عوامل، پوشش رسانه‌ای مدیرعامل از جمله عواملی است که بر همزمانی قیمت سهام تاثیر دارد. به همین خاطر و از جهت اهمیت تاثیرگذاری این عامل که حاکی از چگونگی توجه سرمایه‌گذاران به اطلاعات خاص بنگاه‌های تجاری است، هدف پژوهش حاضر بررسی تاثیر پوشش رسانه‌ای مدیرعامل بر همزمانی قیمت سهام است. در همین راستا، اطلاعات مربوط به 146 شرکت پذیرفته شده در بورس اوراق بهادار تهران طی سال‌های 1390 تا 1398 گردآوری شده و از طریق سیستم معادلات همزمان مورد آزمون قرار گرفته است. یافته‌های مبتنی بر روش گشتاورهای تعمیم یافته(gmm) نشان داد که پوشش رسانه‌ای مدیرعامل تاثیر منفی بر همزمانی قیمت سهام داشته است. همچنین نتایج نشان داد که طبق روش رگرسیون به ظاهر نامرتبط(sur) یک رابطه متقابل بین پوشش رسانه‌ای مدیرعامل و همزمانی قیمت سهام وجود دارد. این یافته‌ها تاکید مجددی بر نقش اطلاعاتی پوشش رسانه‌ای مدیرعامل به عنوان یکی از منابع مخابره اطلاعات شرکتی به بازار وکاهش نقش عوامل غیرسیستماتیک در رفتار قیمتی سهام شرکت‌ها است.

CEO Media Exposure and Stock Price Synchronicity: Simultaneous Equations System

1 IntroductionAn important part of capital market research is relating stock price and its informative, especially the firmspecific information. Accordingly, many studies have been directed on the concept of stock price synchronicity and the factors affecting it, which represent part of stock price informative. In explaining these factors, the CEO media exposure is one of the factors that affect the stock prices synchronicity. 2 Research Questions or hypothesisTherefore, and due to the importance of the impact of this factor, which indicates how investors pay attention to the specific information of businesses, the purpose of this study is to investigate the effect of CEO media coverage on stock price synchronization. 3 MethodsIn this regard, data of 146 firms of Tehran Stock Exchange during the years 2011 to 2019 was collected and tested with the simultaneous equations system. 4 ResultsFindings based on the Generalized Method of Moments (GMM) showed that the CEO media exposure has a negative effect on stock price synchronicity. Also, according to the seemingly unrelated regression (SUR), there is a relationship between CEO media exposure and stock price synchronicity. 5 Discussion and ConclusionThe media as an important and accessible information tool of the society can play a prominent role in informing and informing the stakeholders. This is especially important in economies where transparency is low and information resources are scarce. Accordingly, the purpose of this study was to study the effect of CEO media exposure on stock price synchronicity. The findings show that the CEO’s media exposure had a significant negative effect on stock price synchronicity. Therefore, disclosure of information through the media by managers causes stock prices to be more affected by firmspecific information than market information. Such a move by managers is actually considered a kind of signaling to the market. Because media exposure causes financial transparency and causes the business unit to take steps to provide reliable information, which causes the basis of investors’ decisionmaking to change direction from market and industry news to firmspecific information, and it also has a negative impact on stock price synchronicity. Therefore, CEO media exposure can be considered as one of the tools that has informative content. It is suggested that investors consider the CEO’s media coverage in addition to the fundamental and traditional factors of companies when making their decisions. Because this is important, especially in emerging and less developed markets such as Iran, where there are more barriers to correlation between companyspecific information and stock prices. Also, it is suggested that due to the lack of financial analysts in the Iranian market, as well as excessive fluctuations in risk and return, investors should use the CEO’s media coverage as an alternative to providing and disclosing incomplete information. The media coverage of the CEO can be considered as one of the examples and components of the law for the protection of the rights of microinvestors. It also supports the view that in emerging markets, politically connected firms have wider media coverage, given the complementary findings that reflect the negative impact of CEO coverage on stock price synchronization in higher influential companies. Keywords: CEO Media Exposure, Generalized Method of Moments, Seemingly Unrelated Regression, Stock Price Synchronicity.