Abstract This paper is concerned with the structure and time-consistency of optimal fiscal and monetary policy in an economy without capital. In a dynamic context, optimal taxation means distributing tax distortions over time in a welfare-maximizing way. For a barter economy, our main finding is that with debt commitments of sufficiently rich maturity structure, an optimal policy, if one exists, is time-consistent. In a monetary economy, the idea of optimal taxation must be broadened to include an ‘inflation tax’, and we find that time-consistency does not carry over. An optimal ‘inflation tax’ requires commitment by ‘rules’ in a sense that has no counterpart in the dynamic theory of ordinary excise taxes. The reason time-consistency fails in a monetary economy is that nominal assets should, from a welfare-maximizing point of view, always be taxed away via an immediate inflation in a kind of ‘capital levy’. This emerges as a new possibility when money is introduced into an economy without capital.