This monograph investigates the intersectoral, international, and intertemporal allocation effects of alternative systems of capital income taxation characterized by different degrees of integration between corporate and personal taxation, depreciation rules, provisions for interest deductibility, and the like. The systems studied include those of the OECD countries as well as proposed systems advocated by various authors and tax committees. In contrast to the ``Harberger literature'', the book provides a microfoundation for the analysis of tax distortions. It is not assumed that the various components of capital income taxation can be lumped together as an ``effective tax rate'' that captures all the information relevant for assessing the distortions. Instead, the allocative roles of these components are explicitly derived from the households' and firms' optimization problems. Much emphasis is placed on the tax-induced interaction between the firms' real and financial decisions, and it is argued that this interaction fundamentally changes the nature of many of the tax distortions traditionally claimed for the real economy, sometimes even reversing their direction.