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...

In this paper, the authors present an EOQ model with substitutions between products and a dynamic inventory replenishment policy. Their key assumption is that many products in the market are substitutable at different levels, and that, in most cases, a customer who discovers that a desired...

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...

We look at the theory of arbitrage with taxation under certainty. The tax scale in our model is not linear. Under the premise that tax scale is convex, we analyze prices that do not exhibit arbitrage opportunities. It turns out that there are two kinds of arbitrage: unbounded as well as bounded...

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...