If distinct biological species are to coexist in sympatry, they must be reproductively isolated and must exploit different limiting resources. A two-niche Levene model is analysed, in which habitat preference and survival depend on underlying additive traits. The population genetics of preference and viability are equivalent. However, there is a linear trade-off between the chances of settling ...

The gravity model in economics describes the trade flow between two countries as a function of their Gross Domestic Products (GDPs) and the distance between them. This model is motivated by the qualitative similarity between the desired dependence and the dependence of the gravity force (or potential energy) between the two bodies on their masses and on the distance between them. In this paper,...

OVERVIEW: As demand on fresh water increases, water and environmental managers must trade off potentially conflicting uses of this resource, one of which is the maintenance of aquatic ecosystem integrity (Baron et al. 2002, Postel and Richter 2003, Arthington et al. 2006). In some cases, the process of analyzing trade-offs can identify solutions where numerous outcomes benefit (i.e., win-win sc...

Inter-firm information exchange with respect to the reliability of trade partners may be unmediated in the sense that it involves direct communication between the personnel of two firms. Alternatively, this information flow may be channeled by or through an organization such as a trade association. We assess the relationship between these two mechanisms for conveying reputational information. B...

This article argues that trade in services has a specific feature that does not apply to trade in goods. As the traded service is partly produced where it is consumed (i.e. in the importing country), we propose that it must use interactively inputs from both the exporting and importing countries. The modelling of the specificity of traded services is inspired from the O-ring production function...

The recent development of the telecommunication industries that form the " info structure " environment has enhanced economic activity through improved information technology (IT). IT could enlarge the volume of information flow, which accelerates productivity, but its impact on international trade has not been tested. The main objective of this thesis is to estimate the relationship between te...