Predator-prey relationships account for an important part of all interactions between species. In this paper we provide a microfoundation for such predator-prey relations in a food chain. Basic entities of our analysis are representative organisms of species modelled similar to economic...

According to many observers, the world is currently getting riskier along many of its dimensions. In this paper we analyse how the welfare state, i.e., social insurance that works through redistributive taxation, should deal with this trend. We distinguish between risks that can be insured by...

In this paper we consider a competitive economy with flows of materials from extraction via recycling to landfilling which exhibits distortions due to pollution, external landfilling costs and inefficient product design. The allocative impact of tax-subsidy policies aiming at internalizing the...

This paper analyzes nature protection by a social planner under different "utilitarian" social welfare functions. For that purpose we construct an integrated model of the economy and the ecosystem with explicit consideration of nonhuman species and with competition between human and nonhuman...