It is known that the incompleteness of asset markets causes inefficiency in almost every equilibrium. Yet unexplored is the ”size” of this inefficiency. The size of a Pareto improvement is the total willingness to pay for it, out of current consumption. Inefficiency is the maximum size of...

Focusing on tax policy with incomplete asset markets, we create a framework for proving the existence of Pareto improving taxes, for computing them, and for bounding the improvement. The protagonist is the price adjustment following an intervention. If the price adjustment is sufficiently...

We show that for generic economies, every equilibrium admits Pareto improving monetary policy, even with multiple commodities per state. The main assumption is that asset incompleteness be intermediate, in that household heterogeneity does not exceed the number of assets present and absent. We...

When asset markets are incomplete there are almost always many Pareto improving policy interventions. Remarkably, these interventions do not involve adding any new markets. Focusing on tax policy, I create a framework for proving the existence of Pareto improving taxes, for computing them, and...

When asset markets are incomplete there are almost always many Pareto improving policy interventions, provided there are multiple commodities and households. Remarkably, these interventions do not involve adding any new markets. Focusing on tax policy, I create a framework for proving the...