We calculate the equilibrium fraction of cooperators in a population in which payoffs accrue from playing a single-shot prisoner's dilemma game. Individuals who are hardwired as cooperators or defectors are randomly matched into pairs, and cooperators are able to perfectly find out the type of a...

Quite often established migrants offer assistance and support that facilitate the arrival of new migrants. Why would migrants want other migrants to join them - so much so as to be willing to pay for them to come? We suggest a rationale. Our modeling framework is capable of explaining several...

Our main message is that it is optimal to use less coal and more oil once one takes account of coal being a backstop which emits much more CO2 than oil. The way of achieving this is to have a steeply rising carbon tax during the initial oil-only phase, a less-steeply rising carbon tax during the...

In the environmental economics literature the standard approach of modeling nonlinear production and abatement processes is to treat waste emissions "simply as another factor of production" (Cropper and Oates 1992). That approach doesn't map the materials flow involved completely and hides,...

This paper investigates the relationship between the euro-dollar exchange rate and its underlying fundamentals. First, we develop a simple theoretical model in which chartists and fundamentalists interact. This model predicts the existence of different regimes, and thus nonlinearities in the...

In this paper we develop a micro ecosystem model whose basic entities are representative organisms which behave as if maximizing their net offspring under constraints. Net offspring is increasing in prey biomass intake, declining in the loss of own biomass to predators and Allee's Law applies....