Welfare effects of tax policy in open economies

"This paper studies an international tax policy design problem by employing a two-country dynamic general equilibrium model with incomplete asset markets. We investigate the possibility of welfare improving active tax policies, in particular capital and labor income tax, under the non-cooperative Nash equilibrium and the cooperative equilibrium. Unlike the conventional wisdom regarding stabilization policies, optimal tax policies in our economy are procyclical. Relative to the non-cooperative setting, international tax policy cooperation requires more active tax policies (about two times) and generates large extra welfare gains (by about a third)"--Federal Reserve Board web site.