We provide a comprehensive overview of accounting-related regulatory changes (financial accounting, auditing, tax, and other disclosures) in the 27 European Union countries and the United Kingdom since 1993 based on an extensive literature review, survey, and topic and country expert input. Across all countries and years, we find that more than 16 regulatory events occur in a typical difference-in-differences research design that includes pre- and post-periods of four years. On average 3.4 out of four accounting disciplines are affected, emphasizing the need for interdisciplinary awareness. Our accompanying website ( http://www.eu-regulations.com ) offers visual representations of these events, regulation summaries, literature links, and source documents, all by country. This work aims to (1) lower the cost for researchers, reviewers, and editors to understand the EU’s evolving regulatory landscape; (2) improve research designs by identifying concurrent regulatory events; and (3) highlight research opportunities for those studying the EU or specific member states.

The international dimension of multinational corporations creates opportunities for pursuing both global as well as local (i.e., unilateral subsidiary country) tax planning strategies. To date, however, researchers have limited insights into both the dynamics and relative importance of one versus another strategy for multinationals. We propose and test a group-level ETR-based measure of profit shifting and validate it by showing it correctly identifies profit shifting reductions when shifting costs increase. We confirm that multinationals can keep group ETRs stable after the introduction of tighter tax compliance and documentation rules and suggest they can do so by relying relatively more on local tax planning. In line with the substitution argument, we document that especially groups identified as ex-ante income shifters as well as those with greater target ETR pressure are responsible for the results.

This study investigates the importance of top executives for foreign tax planning in multinational corporations. Applying incremental R 2 comparisons and Shapley Value decompositions, we find that executives account for meaningful variation in foreign tax planning and the number of foreign (tax haven) subsidiaries, but have limited influence on effective tax rates in nonhaven affiliates. We further provide initial evidence that executive influence declined following the Tax Cuts and Jobs Act of 2017 (TCJA), with the decrease being less pronounced for foreign effective tax rates than for domestic ones. Overall, our findings highlight how managers’ influence varies with their firms’ internal structures and external policy changes. Our results contribute to the literature on executive effects, multinational tax planning, and the behavioral implications of tax policy reforms.

We examine whether higher accounting comparability between public and private firms leads to higher value relevance of private firms’ reported financial information. To help develop our hypotheses, we conduct a series of interviews with M&A valuation experts. The experts indicate that comparable accounting between public and private firms allows them to apply public firms’ valuation multiples directly to private firms, which facilitates the use of private firms’ financial reporting in their valuations. Using a large sample of M&A transactions with private target firms in the European Union around the mandatory adoption of IFRS by public firms, we find that private firms’ reported financial information has higher value relevance when it has higher accounting comparability to that of public firms. Furthermore, we find that the impact of accounting comparability is stronger when public peer information is more precise. Our findings are consistent with higher accounting comparability facilitating a spillover of valuation information from public to private markets, which leads to greater value relevance of private firms’ reported financial information.

Key audit matters (KAMs) increase the salience of uncertainty surrounding the underlying accounts. We examine KAMs related to uncertain tax positions (UTPs), which highlight potential concerns to external stakeholders about uncertain tax planning activities such as multinational income shifting. Increased scrutiny may reduce the expected benefits of these strategies and discourage firms from pursuing them. Using KAM disclosures in the expanded audit reports, we find that group-level KAM disclosures are associated with a decline in multinational income shifting when the KAMs relate to UTPs. This relation is stronger when firms are financially unconstrained, when the institutional environment features strong tax enforcement, and when KAMs highlight specific risk statements and auditors provide explicit assurance. Overall, our findings reveal a novel and potentially unintended real effect of expanded audit reports: the salience of tax-related KAM disclosures influences multinational tax planning, highlighting broader consequences of this regulatory intervention. Data Availability: Data are available from the public sources cited in the text.