تأثیر نااطمینانی اقتصاد کلان بر کیفیت افشای اطلاعات مالی شرکت‌های پذیرفته شده در بورس اوراق بهادار تهران

Abstract
This study aims to investigate the impact of macroeconomic uncertainty on the quality of financial information disclosure among the companies listed in the Tehran Stock Exchange. The statistical population consists of 102 firms operating in six industries over a period from 2011 to 2024. To measure the independent variable, a macroeconomic uncertainty index was constructed using a composite indicator based on the volatilities of asset markets (stock market, exchange rate, gold price, and inflation rate), employing GARCH models and principal component analysis (PCA). The quality of financial disclosure was inversely measured using the absolute value of discretionary accruals, estimated through the modified Jones model. To test the hypothesis, a panel data regression with random effects was used. The results show that an increase in macroeconomic uncertainty is associated with an increase in the magnitude of discretionary accruals and, consequently, a decrease in the quality of financial disclosure. This effect is statistically significant in the petrochemical, cement, pharmaceutical, and steel industries, while it is not significant in the auto parts and non-metallic mineral industries. Thus, industry type plays a significant moderating role in this relationship. The findings indicate that, under uncertain economic conditions, managers tend to adopt conservative behavior and restrict disclosed information rather than enhancing transparency. While confirming the political cost hypothesis and the agency theory, the results have important implications for investors, managers, and regulatory bodies. They also emphasize the need for intensified supervisory oversight of financial reporting during turbulent periods.
 
Extended Abstract
Purpose: Macroeconomic uncertainty represents one of the most critical environmental factors that profoundly affect the economic decision-making processes of market participants, regulators, and corporate managers. In an inherently volatile economic environment, the unpredictability of fundamental variables such as inflation, exchange rates, and monetary policies complicates the business landscape, thus making financial planning and resource allocation highly challenging. Consequently, the quality of financial information disclosure, serving as the primary communication channel between firm management and external stakeholders, becomes a focal point of interest. The purpose of this study is to investigate the impact of macroeconomic uncertainty on the quality of financial information disclosure among the companies listed in the Tehran Stock Exchange (TSE). The Iranian capital market provides a unique and compelling setting for this research due to its chronic exposure to structural shocks, international economic sanctions, severe currency fluctuations, and high inflation rates. In such a high-risk environment, managers face a duality; they must choose between enhancing transparency to signal confidence and reduce information asymmetry and engaging in opportunistic earnings management to mask true performance and mitigate proprietary and political costs. This research addresses this gap by utilizing a composite, market-based uncertainty index to empirically determine whether managers lean towards information conservatism or transparency when faced with severe macroeconomic turbulence.
 
Methodology: This study employs a quantitative, an ex-post facto research design using panel data analysis. The statistical population consists of the companies registered in the Tehran Stock Exchange. After applying systematic screening criteria, including the exclusion of financial/insurance institutions and firms with discontinuous fiscal data, a final sample of 102 companies across six major industries (cement, steel, auto parts, pharmaceuticals, petrochemicals, and non-metallic minerals) was selected over a 14-year period from 2011 to 2024.
To measure the independent variable, Macroeconomic Uncertainty (MU), a composite index was constructed. First, the conditional volatilities of four key macroeconomic indicators (stock market returns, foreign exchange rates, gold prices, and the consumer price index) were extracted using Generalized Autoregressive Conditional Heteroskedasticity (GARCH) models. These normalized volatilities were then aggregated using Principal Component Analysis (PCA) to form a single, robust uncertainty metric. The dependent variable, namely the Quality of Financial Disclosure, was inversely proxied by the absolute value of discretionary accruals (|DA|). These accruals were estimated using the cross-sectional Modified Jones Model (1991) and run separately for each industry-year to isolate managerial manipulation from normal business operations. Finally, a panel data regression model with random effects, selected based on the outcomes of the Limer and Hausman tests, was utilized to estimate the relationship between macroeconomic uncertainty and disclosure quality, controlling for firm size, financial leverage, return on assets (ROA), and sales growth. Moreover, separate panel regressions were estimated for each of the six industries to test whether the effect of macroeconomic uncertainty varies across sectors.
 
Findings and Discussion: The empirical findings reveal a positive and statistically significant relationship between the macroeconomic uncertainty index and the absolute value of discretionary accruals at the 1% confidence level. Because discretionary accruals serve as an inverse proxy for disclosure quality, this result indicates that an increase in macroeconomic uncertainty leads to a significant reduction in the quality of financial information disclosure among the sampled firms.
However, this effect is not homogeneous across industries. The industry-level analysis shows that macroeconomic uncertainty significantly reduces disclosure quality in the petrochemical, cement, pharmaceutical, and steel industries, while the effect is not statistically significant in the auto parts and non-metallic mineral industries. In the context of the Iranian economy, these findings suggest that, when faced with severe market risks, currency jumps, and unpredictable inflation, corporate managers prefer to obscure true financial performance. Rather than signaling strength through increased transparency, managers resort to opportunistic accounting choices to manage market expectations, protect proprietary information from competitors, and avoid the potential political costs or regulatory scrutiny associated with volatile profits. The stronger effect in industries with higher profitability and greater government presence (petrochemicals, steel, cement) supports the political cost hypothesis. The control variables also demonstrated significant impacts; higher financial leverage, greater firm size, and higher profitability (ROA) were all associated with increased earnings management, further reducing disclosure quality. Overall, the findings strongly support the transaction cost theory and the information conservatism hypothesis, confirming that high-risk environments encourage managers to restrict transparent financial reporting. The industry-differentiated results represent a key novelty of this study, as prior research mainly reported aggregated findings.
 
Conclusions and Policy Implications: This study concludes that macroeconomic uncertainty serves as a catalyst for reduced financial transparency and diminished disclosure quality in the Iranian capital market. As economic instability rises, managers systematically increase their reliance on discretionary accruals to manipulate earnings, thereby increasing information asymmetry between insiders and external investors. An important additional finding is that this effect is not uniform, it is significant only in the petrochemical, cement, pharmaceutical, and steel industries, but not in auto parts and non-metallic minerals. Thus, industry type plays a crucial moderating role. This conservative and opaque reporting behavior is a defensive mechanism against the severe operational and financial risks prevalent in Iran's sanctioned and inflation-prone economy. The findings of this research, while confirming the political costs hypothesis and the agency theory, have important implications for investors, managers, and regulatory bodies.
From a policy perspective, the findings of this study have important implications for regulatory bodies and policymakers. Given the evidence that the quality of financial disclosure deteriorates during periods of macroeconomic uncertainty, and that this deterioration is more pronounced in the petrochemical, steel, cement, and pharmaceutical industries, it is essential that legal and regulatory authorities reconsider the scope and depth of disclosure requirements. A one-size-fits-all supervisory approach is insufficient; instead, stricter standards should be applied during crisis periods, particularly for these sensitive industries, concerning accruals, accounting estimates, and interim reporting. Continuously strengthening oversight of financial reports and mandating greater transparency in the explanatory notes to the financial statements can significantly curb opportunistic managerial behaviors. Finally, to further develop this line of inquiry in future research, it is recommended that scholars examine the effect of product market competition on disclosure quality under uncertainty separately for high-risk industries, as well as the moderating role of corporate governance mechanisms, such as board independence and audit quality, in mitigating the adverse impacts of macroeconomic factors on financial disclosure quality.