مدیریت سود در سال‌های پس از عرضه اولیه سهام و تأثیر آن بر عملکرد بلندمدت سهام

This study aims to examine the differences in earnings management patterns through current and long-term discretionary accruals in the year following an Initial Public Offering (IPO), compared to the IPO year itself, and to investigate the impact of these patterns on the long-term stock performance of firms listed on the Tehran Stock Exchange (TSE). Earnings management, especially during sensitive periods such as post-IPO years, can significantly influence financial reporting transparency, investor behavior, and overall market efficiency. Drawing on theoretical frameworks including agency theory, signaling theory, market timing theory, and information transparency, four research hypotheses were developed. These hypotheses examine both the temporal shifts in discretionary accrual levels and their subsequent impact on abnormal stock returns over a three-year horizon.



The study sample includes 35 firms that conducted IPOs between 2010 and 2019. Data were collected from financial statements, market performance databases, and stock exchange records. Discretionary current and long-term accruals were separately estimated using the modified Jones model. Long-term stock performance was measured using Buy-and-Hold Abnormal Returns (BHAR) over a 36-month period after the IPO. To test the hypotheses, the study utilized non-parametric Wilcoxon tests (for comparing accrual levels between the IPO and post-IPO years) and multiple regression models, with controls for year and industry effects, and firm-level clustered standard errors.



The results of the first two hypotheses showed no statistically significant differences in the levels of current or long-term discretionary accruals between the IPO year and the following year. This outcome contrasts with common theoretical expectations and suggests that in the Iranian context, persistent economic and institutional conditions—such as inflation, regulatory instability, and financing constraints—may result in consistent earnings management behavior across both periods. However, the third and fourth hypotheses yielded more differentiated results. The study found a significant negative relationship between current discretionary accruals and long-term stock performance. This finding aligns with agency and signaling theories, which posit that opportunistic short-term earnings manipulation can erode investor trust and lead to long-term value destruction. This effect is likely exacerbated in Iran's capital market, where investors rely heavily on financial disclosures and alternative information channels are limited. Surprisingly, the analysis revealed a positive and significant effect of long-term discretionary accruals on long-term stock performance.

This result, which contradicts much of the international literature, may be explained by contextual features of the Iranian market. Investors in high-uncertainty environments may interpret income-smoothing strategies via long-term accruals as signals of managerial stability and prudence. Furthermore, limited regulatory enforcement may delay the detection of earnings manipulation, allowing short- to medium-term gains to dominate investor perception. Overall, this study provides new empirical insights into earnings management behavior in emerging markets and emphasizes the need for localized frameworks when assessing financial reporting quality and stock performance outcomes. The results have practical implications for regulators, auditors, investors, and corporate managers in Iran and similar economies.