Abstract
Increasing cross-border mobility of workers makes the binary distinctions between resident and non-resident dubious as a normative matter and open to manipulation as a practical matter. An alternative to comprehensive income tax systems is a modular tax system that raises revenue through multiple taxes with different criteria for liability. The rise of modular tax systems allows for a more finely calibrated approach to taxing cross-border workers and for rethinking the relationship between citizenship and taxation in two respects. States could levy a modest tax on expatriates maintaining their citizenship while living abroad. Resident citizens might pay additional taxes that support benefits not available to non-citizens. The two proposals complement each other but have very different feasibility conditions. Linking taxation and citizenship in this way does not reflect an inappropriately mercenary approach to civic life, but instead mitigates unfair advantages enjoyed by internationally mobile workers.