This paper organizes, reinterprets and extends the dynamic theory of optimal fiscal policy with a representative agent by using a generalized version of recursive preferences. I allow markets to be complete or incomplete and study a policymaker that acts under commitment or discretion. I highlight the underlying common principles that hide under each particular economic environment. The resulting theories are interpreted through the excess burden of taxation, a multiplier, whose evolution gives rise to different notions of ``tax-smoothing.'' Variants of a law of motion in terms of the inverse excess burden emerge in each environment when we allow for richer asset pricing implications through recursive preferences.
 The basic policy prescription is simple and intuitive and revolves around interest rate manipulation: issue new debt and tax more in the future if this can lead to lower interest rates today.