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"It is widely recognized that many internal migrations are undertaken by individuals whose moves are dependent on those of others. For example, children migrate with their parents and wives with their husbands. This paper suggests two formulations of family migration that permit the introduction of such family dependencies into the population projection process."
OBJECTIVE: To model the potential impact of HIV infection rates and the use of antiretroviral medication on life expectancy and mortality in the Downtown Eastside of Vancouver, British Columbia, Canada, from 1999 to 2006. DESIGN: Population projections were made to estimate the population of the Downtown Eastside in the year 2006. METHODS: Two scenarios were modelled to predict the impact of HIV infection and antiretroviral use on mortality and life expectancy. The use of antiretroviral therapy was estimated to be 80% in the first scenario and 20% in the second. The prevalence of HIV by age and sex, and by year infected was estimated using data from the Vancouver Injection Drug User Study. RESULTS: If the level of antiretroviral therapy use among HIV-positive individuals was 80% at baseline, then we estimate that the life expectancy at birth in the year 2006 will be 60.8 years for men and 72.8 years for women, and 172 AIDS deaths will occur between 1999 and 2006. In contrast, if the present level of antiretroviral medication use persists, the life expectancy at birth in the year 2006 will be 56.9 years for men and 68.6 years for women, and 503 AIDS deaths will occur between 1999 and 2006. CONCLUSION: Our analysis suggests that if the low levels of antiretroviral therapy use persist, life expectancy in Vancouver's Downtown Eastside will soon be on a par with many of the world's least developed countries. Our findings highlight the large health status decline that can be expected in many inner city neighbourhoods if low levels of antiretroviral use persist. Although reasonable coverage targets for injection drug users (IDU) have not been established, the expanded use of antiretroviral medication is urgently needed to avert a drastic decline in health status.
"The purpose of this paper is to analyze the effects of a prolonged period of sustained low fertility upon shifts in the population distribution of the United States among Department of Energy (DOE) regions." The authors also examine the impact of demographic aging on income distribution up to the year 2000 using the assumptions made in the Series III population projections prepared by the U.S. Bureau of the Census in 1977. It is noted that migration will emerge as the primary agent for internal population redistribution.
In response to concerns about the adverse consequences of rapid population growth, family planning programs have been implemented in many developing countries. The aim of the present study is to assess the impact of this programmatic approach on long-range population growth. The result of a new and hypothetical population projection indicates that in the absence of family planning programs the population of the developing world could be expected to reach 14.6 billion in the year 2100 instead of the 10 billion that is currently projected by the World Bank. Despite the apparent success of existing interventions, fertility control is far from complete, as many women continue to bear unwanted births. To assess the impact of this unintended childbearing a second hypothetical projection is made. With perfect implementation of reproductive preferences, the population size of the developing world in 2100 would be reduced by an estimated 2.2 billion below the current projection. Further strengthening of family planning programs and improvements in birth control technology are therefore likely to provide important demographic benefits.
"This paper describes the methodology used to incorporate AIDS mortality in recently revised World Bank population projections.... The paper first reviews different approaches for projecting AIDS and its demographic consequences. This is followed by a summary of an epidemiological model that simulates the spread of HIV used in this analysis, and a demographic model that translates mortality from AIDS into population outcomes. These models are then used in a set of simulations, from which the effect of current HIV prevalence on projected future mortality is extracted. Finally, the extracted equations linking current HIV prevalence with future mortality indicators are applied to sub-Saharan countries with a measurable level of current HIV prevalence."
"In this paper, U.S. Census data is used to examine further the importance of place of birth on migration streams and to trace the impacts of such 'native dependence' on age patterns of migration, multiregional life expectancies, and spatial population projections."
"This study presents population projections for different linguistic components of the Spanish language group, that is, for English dominant bilinguals, Spanish dominant bilinguals and Spanish monolinguals [in the United States]. The population model combines parameters obtained from the U.S. Bureau of the Census for nonlinguistic characteristics with linguistic parameters estimated from the 1976 Survey of Income and Education. The number of persons speaking Spanish on a regular basis will climb to an estimated 16.6 million persons at the turn of the century. Further analysis reveals, however, that an additional 4.5 million persons will have left the group by ceasing to speak Spanish. In fact, in the absence of continued immigration, this language minority cannot maintain its current size and will undergo progressively more rapid decline over the course of time."
"This research note develops a multi-state population projection model in which inter-marriage between the states and the following uncertainty about the state of the children plays a major role. Since only 5% of the Austrian population belong to the Evangelical Church, but more than 80% of their members marry partners not belonging to the church, the question of the percentage of children from mixed marriages that become church members turns out to be vital for the future size and age composition of the church." Five different scenarios to the year 2030 are examined. (SUMMARY IN ENG)
"This paper proposes the use of a log-linear model to obtain long-range micro-level population projections from the aggregative projections. The proposed model is tested using U.S. data. The total population of households is decomposed into 120 subgroups on the basis of the household's region of location, age, size and the female's employment status. The estimated number of households from the log-linear technique is compared against the random-walk and time-trend methods. A comparison of the size of the observed and estimated subgroups for the years 1960 and 1980 suggests that the log-linear technique is superior to the other two methods. Five different measures of errors are used to evaluate the projections."
The authors examine the effects of mortality trends on age structure and how fertility and migration affect demograpnic aging. "Computations are done for both France and Italy on population ageing during the last 30 years as well as until the end of the official population projections around 2040. Though the ageing effect of fertility decline is usually emphasized, we can see here that the consequences of mortality changes are at least equally (and sometimes more) important. The case of the Italian projection is particularly fascinating. Even if the very low fertility level of 1.4 children per capita is maintained until the year 2040, more than half the increase in the proportion of the population aged 60 and over (from 21% to 43% for females) would be due to mortality change and slightly less to fertility change." (SUMMARY IN FRE)
The authors attempt to predict future U.S. immigration trends in light of changing policies. "Changes in policy and the presence of illegal entrants complicates measuring and projecting immigration flows. Acknowledging the risks, this article sketches the possible long-term impact of the immigration trends we observe today, if they were to continue for the next 50 years. This study uses a modified cohort-component approach for population projections by race/ethnicity and immigrant generation."
"This paper [simulates] the impact of demographic change on direct tax revenue for the Netherlands using extensive survey data and population projections. Projected demographic development in the Netherlands fits in well with the OECD mainstream. The analysis thus has a more general relevance. The simulations indicate a 27 percent rise in tax revenue until 2010 because of population growth and a relatively older labor force. After 2030, revenue falls as a consequence of a declining population and a rapidly rising share of the elderly. The authors also simulated a variant in which labor-force participation rates are set on the substantially higher OECD average. In this case, the increase in tax revenue almost doubles as compared to the base variant."
The objective of the computer simulation model described here is to project, for periods up to one or more decades, the annual incidence and prevalence of HIV infection and AIDS in a population with given epidemiological, behavioural and demorgraphic characteristics. In addition, the epidemic's impact on a range of demographic variables is calculated. The epidemiological components of the model use a compartmental approach and they are described with sets of linear differential equations. The demographic framework in which the epidemiological components are integrated, is based on a standard cohort component method of population projection. The simulated population is stratified by age, gender, sexual behaviour, marital status and infection/disease status. The concluding section provides an illustrative application of the model to a Central African population. In this hypothetical simulation covering the period from 1975 to 2000, HIV prevalence in the adult population rises from 0 to 21 per cent. By the end of the projection period mortality is about double the level that would have prevailed in the absence of the epidemic, but, owing to the very high birth rates that prevail in most of Africa, the growth rate of the population remains substantially positive.
The avian auditory brainstem displays parallel processing, a fundamental feature of vertebrate sensory systems. Nuclei specialized for temporal processing are largely separate from those processing other aspects of sound. One possible exception to this parallel organization is the inhibitory input provided by the superior olivary nucleus (SON) to nucleus angularis (NA), nucleus magnocellularis (NM), and nucleus laminaris (NL) and contralateral SON (SONc). We sought to determine whether single SON neurons project to multiple targets or separate neuronal populations project independently to individual target nuclei. We introduced two different fluorescent tracer molecules into pairs of target nuclei and quantified the extent to which retrogradely labeled SON neurons were double labeled. A large proportion of double-labeled SON somata were observed in all cases in which injections were made into any pair of ipsilateral targets (NA and NM, NA and NL, or NM and NL), suggesting that many individual SON neurons project to multiple targets. In contrast, when injections involved the SONc and any or all of the ipsilateral targets, double labeling was rare, suggesting that contralateral and ipsilateral targets are innervated by distinct populations of SON neurons arising largely from regionally segregated areas of SON. Therefore, at the earliest stages of auditory processing, there is interaction between pathways specialized to process temporal cues and those that process other acoustic features. We present a conceptual model that incorporates these results and suggest that SON circuitry, in part, functions to offset interaural intensity differences in interaural time difference processing.
A model developed by J. Nelissen and A. Vossen, for making short-term population projections, is first described. In this model, the fertility rate is related to the unemployment rate and the fraction of the labor force employed in agriculture. The model is then applied to Dutch data for the period 1980-1985. "The main conclusions are that the results depend heavily on the choice of the forecasting period and that the ex-post forecasts of Nelissen and Vossen's model are out-performed by univariate ARIMA-projections." (SUMMARY IN ENG)
"The population of China is still growing despite a dramatic decline in fertility in the past two decades. There are marked urban-rural differentials in fertility and, as a result, the pace of urbanization has significant effects on population growth. In this research an attempt is made to model urban-rural population growth in China. A demoeconomic model of urban and rural sectors is calibrated to account for the long-term trend of urbanization in China.... An accounts-based urban-rural population model, in which rural to urban migration and transition are driven by the foregoing demoeconomic model, is established.... These models are used to make urban-rural population projections for the period 1988-2087 under various fertility rate assumptions."
BACKGROUND: This study documents the number, incidence, and relative risk (RR) of distal forearm fractures requiring admission to hospital in Australia in 1997 and estimates of the projected numbers for 2021. METHODS: Distal forearm fracture numbers from 1993 to 1998 were obtained. The incidence and RR were calculated by gender and 5-year age groups for 1997. Projected numbers for 2021 were estimated using population projection data. RESULTS: In 1997, fracture numbers were 12357 for male patients and 19319 for female patients. The incidence was 152 per 100000 for male patients and 157 per 100000 for female patients. The highest incidence and RR was in the 10- to 14-year age group for male patients and in the 85 years and over age group for female patients. If fracture incidence remains constant (on the basis of predicted population changes in Australia), by 2021, it is estimated that fracture numbers for people 50 years of age and over will increase by 81%, compared with 11% for people under 50. In the older age group, the number for women will be 4.7 times higher than for men. CONCLUSION: This study quantifies the potential disproportionate increase in distal forearm fractures requiring admission in Australia, particularly for female patients, because of an aging population.
"Most laws of mortality are partial in the sense that they apply only to a broad age group and not to all ages. This paper focuses on three laws of mortality that apply to all ages. Two of them were developed by the actuaries Thiele and Wittstein in the late 19th century. The third, developed by Heligman and Pollard, is of recent origin. The three laws are discussed with references to Scandinavian mortality data. The results suggest that the most recently proposed law can be used for generation of model life tables, for making population projections, simulations, and other statistical work where there is a need for a realistic model of human mortality."