We study a structural model of R&D alliance networks in which firms jointly form R&D collaborations to lower their production costs while competing on the product market. We derive the Nash equilibrium of this game, provide a welfare analysis and determine the optimal R&D subsidy program that...

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...

Based on economic methodology we model an ecosystem with two species in predator-prey relationship: mice feed on grain and grain feeds on a resource. With optimizing behaviour of individual organisms a short-run ecosystem equilibrium is defined and characterized that depends on the farmer's use...

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....

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,...

In this paper, location choices are driven by households (both blacks and whites) consciously choosing to trade off proximity to neighbors of similar racial backgrounds for proximity to jobs. Because of coordination failures in the location choices, multiple urban equilibria emerge. There is a...

We develop a model in which non-white individuals are defined with respect to their social environment (family, friends, neighbors) and their attachments to their culture of origin (religion, language), and in which jobs are mainly found through social networks. We found that, depending on how...

Since the 1950s, there has been a steady decentralization of entry-level jobs towards the suburbs of American cities, while racial minorities ?and particularly blacks? have remained in city centers. In this context, the spatial mismatch hypothesis argues that because the residential locations of...

The aim of this paper is to provide a new mechanism for the spatial mismatch hypothesis. Spatial mismatch can here be the result of optimizing behavior on the part of the labor market participants. In particular, the unemployed can choose low amounts of search and long-term unemployment if they...

We investigate the role of spatial frictions in search equilibrium unemployment. For that, we develop a model of the labor market in which workers? location in an agglomeration depends on commuting costs, the endogenous price of land and the value of job search and employment. We first show that...