A relevant mismatch between tax and expenditure decentralization characterizes many industrialized countries. The former is usually less pronounced than the latter, resulting in asymmetric fiscal decentralization arrangements. We investigate the nature of this asymmetry using a theoretical framework that explains why it is difficult to tackle it, despite a consensus on the benefits of a wellbalanced decentralization process. We find that asymmetry is intrinsic to fiscal decentralization, even in a scenario where clear advantages from well-developed decentralized systems arise. This implies that both empirical and theoretical contributions would benefit by taking into account the welfarereducing asymmetric nature of fiscal decentralization.