Digitalization and Tax Planning under BEPS Reforms: Empirical evidence from U.S. Multinational Technology Firms

The rapid expansion of the digital economy has fundamentally transformed corporate tax planning practices, particularly among U.S. multinational technology firms (GAFAM), namely Google (Alphabet), Apple, Meta (Facebook), Amazon, and Microsoft. Despite the implementation of the OECD Base Erosion and Profit Shifting (BEPS) reforms, concerns persist regarding the effectiveness of international tax coordination in constraining profit-shifting activities in the digital sector. Understanding how digitalization interacts with firm-specific characteristics and regulatory interventions remains crucial for designing effective and equitable international tax policies. This study adopts a quantitative and explanatory research design to examine digitalization and tax planning under BEPS reforms using regular annual data for U.S. headquartered GAFAM firms over the period (2010–2024). The empirical analysis applies an Auto-Regressive Distributed Lag Error Correction Model (ARDL-ECM) to capture both short-run adjustments and long-run equilibrium dynamics, complemented by stepwise regression models to account for firm-specific heterogeneity. The empirical framework incorporates digitalization intensity, R&D intensity, capital expenditures, goodwill and intangible assets, profit-shifting intensity, BEPS reforms, and an interaction term between BEPS reforms and profit-shifting intensity as key determinants of effective tax rates. The results indicate that profit shifting remains the main driver of effective tax rate variations, while BEPS reforms significantly constrain tax planning opportunities in both the short and long run. However, digitally intensive firms strategically adapt, partially preserving tax advantages. Digitalization, R&D activities, capital expenditures, and intangible assets primarily influence effective tax rates indirectly through their impact on profit-shifting behavior, with investment-related effects appearing with delays consistent with amortization and adjustment cycles. Overall, the findings highlight the partial effectiveness of BEPS reforms and the continued adaptability of U.S. multinational technology firms, providing robust longitudinal evidence for policymakers aiming to curb digital profit shifting while maintaining incentives for innovation and productive investment.