This series of research reports deals with the status of the elderly in several Asian countries. It presents research that is being conducted under a broad project sponsored by the U.S. National Institute on Aging, the Comparative Study of the Elderly in Four Asian Countries (Grant No. AGO7637). The goal is to measure the social, economic and health characteristics of the older population (age ...

Random copying is a simple model for population dynamics in the absence of selection, and has been applied to both biological and cultural evolution. In this work, we investigate the effect that spatial structure has on the dynamics. We focus in particular on how a measure of the diversity in the population changes over time. We show that even when the vast majority of a population’s history ma...

Many simple population models exhibit the period doubling route to chaos as a single parameter, commonly the growth rate, is increased. Here we examine the effect of an immigration process on such models and explain why in the case of one-dimensional ("single-humped") maps, immigration often tends to suppress chaos and stabilise equilibrium behaviour or cyclical oscillations of long period. The...

In this paper, we would like compare the spread of an infectious disease in a population without the influence of a predator and under its influence. We show that it is possible to control an epidemic in a population with the help of predators.

A new multivariate approach is introduced to identify the middle class of a society and to measure its possible decline. The middle class is a properly defined central region in attribute space that contains a fixed portion of the population. The decline of the middle class is measured by comparing volumes of the middle class. The use of different notions of central regions is discussed in one ...

A growing body of literature has led to the debate in invasion biology whether exotic species perform within communities differently than native taxa due to inherent advantages. To address this issue, the population dynamics of native and exotic plant species were assessed from a 48-year record of permanent plot data from the Hutcheson Memorial Forest Center (New Jersey, USA) to determine rate ...

Using data for six Asian miracle economies over the period from 1953 to 2006, this paper examines the extent to which growth has been driven by R&D and tests which second-generation endogenous growth model is most consistent with the data. The results give strong support to Schumpeterian growth theory but only limited support to semi-endogenous growth theory. Furthermore, it is shown that R&D h...

Suppose that in symmetric aggregative games, in which payoffs depend only on a player’s strategy and on an aggregate of all players’ strategies, players have conjectures about the reaction of the aggregate to marginal changes in their strategy. The players play a conjectural variation equilibrium, which determines their fitness payoffs. The paper shows that only consistent conjectures can be ev...

This paper brings both intertemporal and age-dependent features to a theory of population policy at the macro-level. A Lotka-type renewal model of population dynamics is combined with a Solow/Ramsey economy. We consider a social planner who maximizes an aggregate intertemporal utility function which depends on per capita consumption. As control policies we consider migration and saving rate (bo...