آیا پذیرش XBRL عدم تقارن اطلاعات را کاهش می دهد؟

This paper examines whether or not XBRL (eXtensible Business Reporting Language) adoption reduces information asymmetry in a stock market context. Student t-tests and multiple regression analysis were employed to examine the effect of XBRL adoption on information asymmetry in the capital market. A significant and negative association exists between XBRL adoption and information asymmetry, which implies that the adoption of XBRL may lead to the reduction of the information asymmetry in the Korean stock market. In addition, the effect of XBRL adoption on reducing information asymmetry is stronger for large-sized companies than for medium-sized and small-sized companies. Based on these findings, the demand for XBRL-enabled applications and services in the capital market is expected to grow while governments should promote XBRL adoption for business reporting.

Many companies use the World Wide Web (WWW or web) as one of the primary means for reporting corporate information (Debreceny and Gray, 2001). The content of corporate information on the web is not very different from financial disclosures on paper-based documents. This content has been standardized for human review, not for automatic location, acquisition, arrangement and classification. Information is hard to find unless one knows which form to search and the data in those forms cannot be downloaded into spreadsheets or other application software (SEC (U.S. Securities and Exchange Commission), 2006). As a result, corporate information on the web cannot adequately meet the demand of stakeholders for various analyses of corporate data. Additional technical components must be deployed that support the decision-making capabilities of stakeholders and XBRL (eXtensible Business Reporting Language) is an approach to achieve this. XBRL is one variant of XML (eXtensible Markup Language) for business reporting. XBRL defines financial data on the web with explicit semantics in a machine-readable format, making automated data analysis possible. Adopting XBRL facilitates communications among market players and enhances the quality of stakeholder decisions. Business reporting in the XBRL format is also important to filing companies. If a company provides financial reports in a high-quality, standard format, investors are likely to appraise the company as less risky. This could lead to the decrease of capital cost and the increase of the firm's stock price. Diamond and Verrecchia (1991) report that if the level of disclosures is increased, the level of information asymmetry is decreased, resulting in more demand from investors. If the level of financial disclosures is increased by adopting XBRL, information asymmetry is expected to be reduced, which could lead to the decrease of the cost of capital and the increase of a firm's valuation. This study examines whether the adoption of XBRL has reduced the level of information asymmetry in the Korean stock market. Korea is one of the leading countries that have developed a mandatory filing program in XBRL format. This policy has been in effect in Korea since October 2007, thus the Korean stock market is an appropriate target market to investigate the initial effect of XBRL adoption. The principal focus of this study is to empirically examine whether XBRL adoption can reduce information asymmetry in the capital market. While previous studies have primarily investigated the effects of the short-term provision of corporate information (e.g., earnings announcements) on information asymmetry, this paper focuses on the fundamental change of the technological environment affecting information asymmetry. The next section of the paper describes the concept and benefits of XBRL and reviews the literature of corporate disclosures and information asymmetry. Hypotheses about the relationship of XBRL and information asymmetry are then developed followed by a description of the data used in the analysis and how information asymmetry is measured. The next sections contain findings of the analysis along with a discussion of the implications of this research.

Accounting and finance research argues that an increased level of corporate disclosure lowers the information asymmetry of the capital market. Numerous experts insist that XBRL adoption enhances the transparency and quality of business reporting, so XBRL adoption should decrease the information asymmetry of the capital market. This study examines the relationship between XBRL adoption and information asymmetry in the capital market. This study supports the conclusion that XBRL adoption reduces the information asymmetry of the Korean stock market. Highly significant and negative associations between XBRL adoption and information asymmetry of the capital market were found after controlling for potentially confounding factors, such as firm size, turnover rate, volatility, and stock price. This study also examines the effect of XBRL adoption on reducing information asymmetry for large-sized firms over medium-sized and small-sized firms. The effect of XBRL adoption is stronger for large firms than for small firms. This study has a few limitations. First, a relatively short period after XBRL adoption (nine months) was examined. Korea was one of the leading countries in the world to require using XBRL in business reporting (FSS (Financial Supervisory Service), 2007), but less than two years later, the global financial crisis severely changed the capital market. Further analysis with a longer sampling window is necessary to verify the benefits of XBRL adoption. Second, the effect of XBRL adoption on reducing information asymmetry was examined, focusing on the benefits for investors. Future research should examine additional benefits of XBRL adoption for various stakeholders. This study also has several implications. First, evidence of the benefits from XBRL adoption was illustrated by examining the Korean stock market. These findings can be an empirical and theoretical foundation to accelerate the adoption of XBRL in other countries. The effect of XBRL on reducing information asymmetry enhances the quality of valuation for firms and decreases capital cost. The results of this study provide strong incentives for firms to provide XBRL-enabled applications and services to their stakeholders. Consequently, the demand for XBRL-enabled applications and services in the capital market will continue to grow. Finally, this study found that XBRL adoption is not significant for medium-sized and small-sized companies. A broader deployment of XBRL-enabled applications and services is needed, which could be aided by greater cooperation among the various stakeholders, such as filing companies, solution vendors, service providers, and government agencies.