This paper examines the role of personal income taxes on multinationals' corporate tax-induced profit shifting. As mandated in most OECD countries, firms need economic substance in low corporate-tax countries to justify profit shifting to these countries. Because high personal income taxes raise labor costs and thus the cost of providing economic substance, we predict that personal income taxes mute profit shifting. Using data from 26 European countries, we find that personal income taxes substantially reduce profit shifting to low corporate-tax jurisdictions, particularly when parent countries impose strict substance requirements. We also find that firms use employees to justify economic substance and that the effect of the personal income tax is related to its incidence falling partly on firms. Our results show important interactions between personal and corporate income taxes that reduce multinationals’ profit-shifting activities when substance requirements are implemented as in the European Union or many OECD countries.

This article studies how corporate tax hikes transmit across countries through multinationals’ internal networks of subsidiaries. We build a parsimonious multicountry model to highlight two opposing spillover effects: while tax competition between countries generates positive investment spillover, intra-firm production linkages predict negative spillover. Using subsidiary-level data and exogenous corporate tax hikes, we find that local business units cut investment by 0.5 percent for a 1 percent increase in foreign corporate tax. This result highlights the importance of production linkages in propagating foreign tax shocks, as the supply-chain-induced negative spillover dominates the positive spillover effect suggested by the conventional wisdom of tax competition.