Throughout the industrial world and in much of the Third World, populations are aging. This population aging results in part from lower fertility and in part from longer life. Lower fertility reduces the rate of population growth, so that recent generations are smaller than earlier generations, and therefore the relative number of older people is greater. This kind of aging raises the share of ...

in his brilliant editorship of Population and Development Review, Paul demeny encouraged both types of research on demographic change. this essay is in the spirit of the first type of study. rather than dealing with the entire population, however, it restricts its attention to ages above 65, where population changes reflect, amplify, and reshape the broad patterns associated with the demographi...

Scores developed by using parametric or nonparametric classification approaches based on profile characteristics are basic tools for portfolio management. Changes in factors like the economy, culture, or age would cause shifts in the profile characteristics for individuals or business entities. The change would, in turn, mean changes in any decision supporting algorithms based on profile charac...

"We examine spatial patterns and their changes during the 1970s for the Los Angeles region, by estimating monocentric and polycentric density functions for employment and population. Downtown Los Angeles is clearly identified as the statistical monocentric center of the region, and it is the most consistently strong center in the polycentric patterns. Polycentric models fit statistically bette...

Previous empirical studies of population size and language change have produced equivocal results. We therefore address the question with a new set of lexical data from nearly one-half of the world's languages. We first show that relative population sizes of modern languages can be extrapolated to ancestral languages, albeit with diminishing accuracy, up to several thousand years into the past....

Here, the population transfer between two specific levels of Cesium atomunder the influence of chirped laser source has been numerically investigated. The maingoal of this study is the engineering of the population transfer between the 62S1/2 and 62P1/2levels of Cesium which is corresponding to its D1 transition line using a chirped lasersource. Constructing the system Hamiltonian, as well as t...

Phenological trends provide important indicators of environmental change and population dynamics. However, the use of untested population-level measures can lead to incorrect conclusions about phenological trends, particularly when changes in population structure or density are ignored. We used individual-based estimates of birth date and lactation duration of harbour seals (Phoca vitulina) to ...

With the world’s population set to increase by 65% (3.7 billion) by ∼2050, the additional food required to feed future generations will put further enormous pressure on freshwater resources. This is because agriculture is the largest single user of fresh water, accounting for ∼75% of current human water use. At present ∼7% of the world’s population live in areas where water is scarce. This is p...