In a partial equilibrium setting without price uncertainty, the balanced-budget substitution of an ad valorem tax on output for a specific (unit) tax can enhance welfare in imperfectly competitive markets and is without impact in a competitive world. This paper demonstrates that a substitution...

Applying a framework of perfect competition under uncertainty, we contribute to the discussion of whether or not ad valorem taxes and specific taxes are equivalent. While this equivalence holds without price uncertainty, we show that ad valorem taxes and specific taxes are “almost never”...

We model the optimal reaction of a public PAYG pension system to demographic shocks. We compare the ex-ante first best and second best solution of a Ramsey planner with full commitment to the outcome under simple third best rules that mimic the pension systems observed in the real world. The...