A survey of the literature on optimal taxation both in infinitely-lived agent models and life-cycle economies suggests that no consensus emerges regarding the optimal tax rate on capital income. Although the tax rate is invariably zero in the long-run steady state of infinitely-lived agent...

We use a very standard life-cycle growth model, in which individuals have a labor-leisure choice in each period of their lives, to prove that an optimizing government will almost always find it optimal to tax or subsidize interest income. The intuition for our result is straightforward. In a...