Financial innovation in an existing asset generically supports a Pareto improvement, targeting the income effect. This result, as several on taxation, owes to one unifying notion: that an intervention generically supports Pareto improvements if the implied price adjustment is sufficiently...

Samuelson (1947) stated that a regular equilibrium exhibits the transfer paradox if and only if it is unstable. Gale (1974) and many in the early 1980’s debunked this equivalence by adding extra countries, reaching an anti consensus. We reinterpret Samuelson’s result as identifying the...