The causal impact of the IFRS adoption roadmap on the value relevance of accounting information: evidence from Vietnam

Purpose This study investigates the causal effect of Decision No. 345/QÐ-BTC (2020) Vietnam's official roadmap for IFRS adoption on the value relevance (VR) of accounting information. Focusing on an emerging market with evolving legal enforcement, it examines whether earnings per share (EPS), book value (BV) and cash flows (CFS) better reflect firms' market value following the policy's enactment. Design/methodology/approach Using 10,660 firm-year observations from 2016–2024, the study applies a staggered difference-in-differences (DiD) design. Listed firms on HOSE and HNX form the treatment group, while UPCOM firms serve as the control group due to lower regulatory intensity and indirect exposure to the IFRS roadmap. Robustness is ensured through parallel trends tests, coarsened exact matching (CEM), a placebo test for 2018 and multi-way fixed-effects regressions. Findings The results reveal a significant post-policy increase in the value relevance of accounting information, most notably for EPS (p 0.01). In contrast, the value relevance of BV declines in interaction models, highlighting implementation challenges related to fair value measurement in a low-liquiity market with regulatory gaps. The positive impact of IFRS is stronger for large firms and formally listed companies, emphasizing the role of compliance capacity and market monitoring. Practical implications The findings support continuing the IFRS adoption roadmap while underscoring the need to address regulatory delays, particularly in conversion guidance and tax alignment. IFRS-compliant reports also function as quality signals that reduce information asymmetry for investors in volatile markets. Originality/value This is the first study to provide causal evidence on IFRS policy effects in Vietnam using a staggered DiD approach. It contributes to Institutional and Signaling theories by showing substitution effects among accounting metrics enhancing earnings relevance while attenuating BV relevance under weak enforcement, with a framework applicable to other transition economies.