Several agent-based frameworks have been proposed to investigate the possible reasons that lead humans to act in the interest of others while giving up individual gains. In this paper we propose a novel framework for analyzing this phenomenon based on the notions of social importance and local discrimination. We propose a “favors game”, where a recipient agent can “claim” a favor to a donor age...

To gain a clearer understanding of the dynamics of evolving populations the limit of innnitely long strings is examined. The limit clariies some of the behaviour of evolving systems. For example, this limit removes any complications due to transient behaviour. Care is required in taking the limit to ensure that the quantities considered are meaningful. For concreteness a simple Genetic Algorith...

Building on the tradition of research in organizational ecology and institutional theory, this article extends our understanding of how legitimacy contributes to the creation of new organizational populations. Ecologists have observed that both legitimacy and competition operate through density-dependent processes to affect patterns of organizational foundings. Drawing on Aldrich and Fiol (1994...

This study examines the expansion of visible minority neighbourhoods in Canada’s three largest metropolitan areas. Minority neighbourhoods, defined as census tracts with over 30% of their population from a single visible minority group, increased in number from 6 to 254 between 1981 and 2001. Most of these neighbourhoods were formed through a partial replacement of nonvisible minority residents...

This paper introduces a class of stochastic models of interacting neurons with emergent dynamics similar to those seen in local cortical populations, and compares them to very simple reduced models driven by the same mean excitatory and inhibitory currents. Discrepancies in firing rates between network and reduced models were investigated, and mechanisms leading to these discrepancies were iden...

Evolution’s ability to find innovative phenotypes is an important ingredient in the emergence of complexity in nature. A key factor in this capability is evolvability, or the propensity towards phenotypic variation. Numerous explanations for the origins of evolvability have been proposed, often differing in the role that they attribute to adaptive processes. To provide a new perspective on thes...

We present an explicit solution to a classic model of cell-population growth introduced by Luria and Delbrück [1] 70 years ago to study the emergence of mutations in bacterial populations. In this model a wild-type population is assumed to grow exponentially in a deterministic fashion. Proportional to the wild-type population size, mutants arrive randomly and initiate new sub-populations of mut...

Oak-hickory forests of the Arkansas Ozarks recently incurred extensive tree mortality due in part to a native wood-boring beetle, the red oak borer Enaphalodes rufulus (Haldeman) (Coleoptera: Cerambycidae). Historically, red oak borer has existed throughout southeastern U.S. forests at relatively low population levels, but Arkansas infestation estimates in 2001 and 2003 reported much higher pop...

This paper examines the impact of manufacturing import growth on agricultural productivity for a small open economy using a 2× 2 sector endogenous growth model. We show that the increase of import variety share in manufacturing, when there is no trade induced labor reallocation, drives the emergence of a sectoral productivity growth gap: productivity growth in agriculture is lower than in manuf...

Rural communities in India are often underserved by the mainstream media. While there is a public discourse surrounding the issues they face, this dialogue typically takes place on television, in newspaper editorials, and on the Internet. Unfortunately, participation in such forums is limited to the most privileged members of society, excluding those individuals who have the largest stake in th...