As a response to a changing labour market scenario and to the concerns for increasing costs and bad incentives of traditional income support policies, the last decades have witnessed, in many countries, reforms introducing more sophisticated designs of means-testing, eligibility and tagging. In...

We solve the problem of a social planner who seeks to minimize inequality via transfers with a fixed public budget in a distribution of exogenously given incomes. The appropriate solution method depends on the objective function: If it is convex, as in the case of the absolute mean deviation, it...

We study the optimal control of a pollutant that accumulates with a delay.We find that optimal paths are, in general, non-monotonic and oscillatory, but monotonic if the objective function is additively separable. Hence, using additively separable objective functions as an approximation to a...

In a less widely known contribution, Béla Martos (1966, Hungarian Academy of Sciences) introduced a generalized notion of concavity that is closely related to what is nowadays known as r-concavity in the operations research literature, and that is identical to what is nowadays known as...

According to a widely held belief, all who are able to work, should workʺ. We consider this statement within a framework of non-linear taxation. The crucial difference between our model and the standard model is that the government can distinguish between productive persons and the disabled. A...