ABSTRACTWe investigate whether tax avoidance and manager diversion are complementary when the costs of diversion are low by comparing dividend payouts, performance, and overinvestments of tax haven firms versus other multinational firms based in countries with weak and strong investor protections. Desai and Dharmapala (2006, 2009a, b) and Desai et al. (2007) set forth a theory of tax avoidance within an agency framework (the D&D theory) based on the assumption that tax avoidance and manager diversion are complementary when the corporate governance system is “ineffective” (i.e., the manager's expected costs of diversion are low). Tax haven firms are corporate groups whose parent firms are incorporated in tax haven countries that are not the countries where the groups’ headquarters or primary operations are located (i.e., their “base” countries). We argue that tax haven incorporation potentially lowers the costs of diversion for managers of firms based in countries with weak investor protections. Using a sample from 28 base countries, we provide evidence that manager diversion and tax avoidance are complementary for tax haven firms based in countries with weak investor protections but not for tax haven firms based in countries with strong investor protections. Our results are consistent with the complementarity assumption underlying the D&D model and provide additional insights into the potential impact of the decentralization of the global firm.