Age Structure Of Population Research Articles

Based on the Analysis of Existing Economic Policies, Compares the Response of Economic Policies to Population Ageing between the UK and Japan

In the context of the changing age structure of the global population, many countries are experiencing the economic consequences of this problem, such as severe dependency ratios and a reduction of qualified workers, which will harm the country's potential economic growth capacity. In order to mitigate the negative effects on the economy, both Japan and the United Kingdom have developed economic policies to deal with population ageing. These policies all revolve around healthcare, pension and employment. These economic policies are similar in some respects, such as in employment, where the two countries try to raise the retirement age of the elderly from various aspects, but show different policy biases in further policy-making for different reasons, such as different cultural backgrounds. This paper analyzes these similarities and differences by reviewing past literature and policy cases, making preliminary conjectures and summaries on the causes of these characteristics through past literature, and analyzing the effectiveness of some of these policies. Finally, we conclude from the study that these policy differences are due to different cultural, and historical backgrounds and current economic situations between the two countries.

Age-specific all-cause mortality trends in the UK: Pre-pandemic increases and the complex impact of COVID-19

ObjectivesThis study aims to analyse age-specific all-cause mortality trends in the UK before and after COVID-19 emergence to determine if pre-pandemic trends contributed to increased mortality levels in the post-pandemic era. Study designStatistical analysis of UK mortality data. MethodsWe utilised age-structured population and mortality data for all UK countries from 2005 to 2023. Mortality rates were calculated for each age group, and excess mortality was estimated using the Office for National Statistics (ONS) method. ResultsOur most concerning finding is an increase in all-cause mortality rates for middle-aged adults (30–54 years) starting around 2012. The COVID-19 pandemic may have further impacted these rates, but the pre-existing upward trend suggests that current elevated mortality rates might have been reached regardless of the pandemic. This finding is more alarming than the slowdown in the decline of cardiovascular disease death rates for individuals under 75 noted by the British Heart Foundation. ConclusionOur results highlight the importance of considering both immediate pandemic impacts and long-term mortality trends in public health strategies. This underscores the need for targeted interventions and improved healthcare planning to address both ongoing and future challenges.

Variety is the spice of life: nongenetic variation in life histories influences population growth and evolvability.

Individual vital rates are key determinants of lifetime reproductive success, and variability in these rates shapes population dynamics. Previous studies have found that this vital rate hetero- geneity can influence demographic properties including population growth rates, however, the explicit effects of the amount of variation within and the covariance between vital rates that can also vary throughout the lifespan on population growth remains unknown. Here, we explore the analytical consequences of nongenetic heterogeneity on long-term population growth rates and rates of evolution by modifying traditional age-structured population projection matrices to incorporate variation among individual vital rates. The model allows vital rates to be permanent throughout life ("fixed condition") or to change over the lifespan ("dynamic condition"). We reduce the complexity associated with adding individual heterogeneity to age-structured models through a novel application of matrix collapsing ("phenotypic collapsing"), showing how to col- lapse in a manner that preserves the asymptotic and transient dynamics of the original matrix. The main conclusion is that nongenetic individual heterogeneity can strongly impact the long-term growth rate and rates of evolution. The magnitude and sign of this impact depends heavily on how the heterogeneity covaries across the lifespan of an organism. Our results emphasize that nongenetic variation cannot simply be viewed as random noise, but rather that it has consistent, predictable effects on fitness and evolvability.

Population re-establishment and spatial dynamics of crowberry (Empetrum nigrum ssp. hermaphroditum), a foundation species in restored alpine ecosystems.

Many ecosystems are defined and shaped by one or a few common, foundation species. Even though such species hold a key role in the restoration of these ecosystems, the demographic processes involved in their re-establishment have rarely been studied. Foundation species' population dynamics, re-establishment history, and the abiotic and biotic factors that affect individual establishment at restored sites can be studied by addressing population spatial patterns and age structure. Such an approach to studying population dynamics is particularly relevant for long-lived species with low mortality, such as shrubs in alpine areas. We studied a population of the foundation species Empetrum nigrum ssp. hermaphroditum at an alpine spoil heap site and found evidence of population re-establishment starting within a decade after construction. High Empetrum densities close to the spoil heap edges indicated that short distances to seed sources in the surroundings had a strong positive effect on establishment of individuals. Empetrum individuals were significantly clustered, which indicated intraspecific facilitation. As revealed by spatial analyses of recruits and older, established individuals, clustering developed gradually over time, which indicated a shift from no interaction to increased facilitation. We conclude that intraspecific facilitation promotes Empetrum reestablishment at the studied alpine spoil heap. Synthesis: We show that population spatial patterns and age structure can be successfully used to unveil the re-establishment history of a foundation species in a restoration context. Efficient seed dispersal and intraspecific facilitation seem to be important factors behind Empetrum's successful re-establishment at alpine spoil heaps. Identification of abiotic and biotic factors determining foundation species' establishment success at restored sites can support planning and improve success of restoration.

Trend and driving factors in burden of age-related macular degeneration in older adults aged 60-89years: a global analysis over three decades.

To explore temporal trends and determine driving factors of age-related macular degeneration (AMD) burden in older adults aged 60-89years at global, regional and national levels from 1990 to 2019. Prevalence and years lived with disability (YLDs) were extracted. Joinpoint regression analysis was adopted to calculate average annual percentage change and to identify the year with the most significant changes. Global trends were stratified by sex, age and sociodemographic index, and regional and national trends were explored. Decomposition analysis was conducted to determine what extent the forces of population size, age structure and epidemiologic change driving alterations of AMD burden. Globally, prevalence rate slightly increased whereas YLDs rate decreased. The year 2005 marked a turning point where both prevalence and YLDs started to decline. Regionally, Western Sub-Saharan Africa had the highest prevalence and YLDs rates in 2019, with East Asia experiencing the most notable rise in prevalence from 1990 to 2019. Global decomposition revealed that the increased case number was primarily driven by population growth and ageing, and epidemiological change was only detected to lessen but far from offset these impacts. Although there was only slight increase or even decrease in prevalence and YLDs rates of AMD in older adults, the case number still nearly doubled, which may be primarily attributed to population growth and ageing, coupled with the emerging growing pattern of prevalence rate from 2015, collectively suggesting a huge challenge in control and management of AMD.

서울시 인구변화와 중고령기 수면건강 - 외국인 밀집정도와 지역사회 응집력의 상호작용을 중심으로

This study examines whether neighborhood demographic characteristics are associated with sleep health among Korean older adults and whether this association is moderated by neighborhood social cohesion. Data are drawn from the 2019 Seoul Survey Data (SSD) merged with various sources of contextual data to assess information on population loss, age structure and immigrant concentration at the Gu level (N=20,319). We defined poor sleep health as respondents reporting six hours or less of sleep (coded 1; otherwise 0) Results from multilevel logistic regression model indicated that older adults who live in neighborhoods with high levels of immigrant concentration are more likely to experience poor sleep health. However, this association was mitigated by neighborhood social cohesion, such that those who have high levels of neighborhood social cohesion appear to be less influenced by immigrant concentration. This study suggests that neighborhood social cohesion may play a buffering role in minimizing the negative influence of neighborhood immigrant concentration on sleep health among older adults in Korea. Social policy and intervention aimed at promoting social cohesion may help reduce further disparities in poor sleep health in later life.

Identification of the local changes in age-structured population dynamics with missing initial condition

In this paper, we study an inverse problem consisting of determining the unknown local changes of a population densities independent of the missing initial population age distribution from the knowledge of some measurement in the state. The main idea is to transform the study of the inverse problem into an optimal control problem with incomplete data. To solve this kind of problem, we use the method of no-regret control approximated by a sequence of low-regret control. We show the existence and uniqueness of the sequence of low-regret control, which converges weakly to the unique no-regret control. The local changes are characterized by a coupled optimality system.

How does chronic disease influence subjective life expectancy among middle-aged and older adults? Evidence from the China Health and Retirement Longitudinal Study (CHARLS) 2018 cross-sectional data.

Chronic diseases have become one of the most important factors threatening human health. Subjective life expectancy (SLE) describes an individual's expectation or subjective perception of lifespan. This article aims to explore the relationship between chronic diseases and SLE, as well as the differences among different age groups and different types of chronic diseases in this relationship. China Health and Retirement Longitudinal Study (CHARLS) is a nationwide longitudinal study that evaluates the social, economic, and health conditions of middle-aged and older adult families and individuals aged 45 and above in China. In this study, CHARLS used probability proportional to size sampling (PPS sampling) to ensure the breadth and representativeness of the sample. This study selected cross-sectional data from CHARLS 2018, removed missing values, and obtained a valid sample of 10,658 middle-aged and older individuals, of whom 8564 had chronic diseases. After controlling demographic, health behavior, socioeconomic, psychological, and social security factors, an ordered logistic regression was performed to explore the relationship between chronic disease and SLE in middle-aged and older adults. The results show that chronic diseases negatively correlate with SLE in middle-aged and older adults. Middle-aged and older adults with chronic diseases are 36.2% less likely to have high life expectancy than those without chronic diseases. Many different types of chronic diseases are negatively correlated with SLE. Cancer is most negatively correlated with SLE, far exceeding other chronic diseases. Chronic disease and SLE of middle-aged and older adults have age-heterogeneous differences. For middle-aged people aged 45-59 and young older adults aged 60-79, there is a significant correlation between chronic diseases and SLE. However, there is no correlation between chronic diseases and subjective life expectancy in the older population aged 80 and above. The government and society should pay close attention to the prevention and treatment of chronic diseases among middle-aged and older adults and adjust policies and measures according to the population's age structure. In addition, the government and society should pay attention to the spiritual needs of middle-aged and older adults. The government and society should pay more attention to cancer patients. Finally, the scientific research team should also strengthen research on chronic diseases, research and development of specific drugs and vaccines, improve the cure rate of chronic diseases, promote people's health, and make people no longer afraid of diseases.

Overcompensation of transient and permanent death rate increases in age-structured models with cannibalistic interactions

There has been renewed interest in understanding the mathematical structure of ecological population models that lead to overcompensation, the process by which a population recovers to a higher level after suffering a permanent increase in predation or harvesting. Here, we apply a recently formulated kinetic population theory to formally construct an age-structured single-species population model that includes a cannibalistic interaction in which older individuals prey on younger ones. Depending on the age-dependent structure of this interaction, our model can exhibit transient or steady-state overcompensation of an increased death rate as well as oscillations of the total population, both phenomena that have been observed in ecological systems. Analytic and numerical analysis of our model reveals sufficient conditions for overcompensation and oscillations. We also show how our structured population partial integrodifferential equation (PIDE) model can be reduced to coupled ODE models representing piecewise constant parameter domains, providing additional mathematical insight into the emergence of overcompensation.

Analysis and optimal control of a hierarchical age-structured population model in a polluted environment

For individual biological populations, examining the impacts of competition within the species and the presence of toxic substances in the environment can effectively facilitate control measures. However research in this area remains limited. This article introduces a toxicant-population model incorporating a hierarchical age-structured and examines the minimum deviation problem within this model. The aim is to explore effective control strategies that strike a balance between improving the environment and population benefits. Through a novel approach, we reformulate the problem as an abstract Cauchy problem on a non-dense domain and then apply integrated semigroup theory to establish the existence, uniqueness, and positivity of solutions to the model. The existence of optimal control is derived using Ekeland's variational principle in functional analysis. The expression for optimal control is given by the Pontryagin's minimum principle. Lastly, we conducted numerical experiments on the model, applied optimality conditions to delineate optimal control, and illustrated the comparison between crucial population parameters under optimal control and those without any control.

Population Size, Sex-Ratio and Age Structure of Hippopotamus Amphibius in Nimule National Park, South Sudan

Population Size, Sex-Ratio and Age Structure of Hippopotamus Amphibius in Nimule National Park, South Sudan

Leslie Matrix Model For Euphorbia Hirta L Population

Invasive species management has developed into a highly specialized field utilizing a systems approach. It requires knowledge of their life history, growth requirements, and population dynamics that integrate their biology and control. The foundation of strategic planning for the management of invasive species is laid by demographic studies, which record the birth, growth, reproduction, and death of individuals within a population. The present study makes use of the Discrete Leslie Matrix Model to analyze the growth in the age-structured population of Euphorbia hirta, an invasive species in agrosystems, identify critical stages in the species' life cycle, and project the structure and size of future population.

A Cost-Benefit Analysis of Alternative Management Strategies for Red Deer in Denmark

In this paper, we conduct a cost-benefit analysis (CBA) of five alternative management strategies for red deer in Denmark: free harvest, trophy hunting, maximum harvest and two cases for natural demographic population compositions. To capture the outcome under each strategy we use a biological sex- and age-structured population model. The net benefit function includes meat values, recreational values, browsing damage costs and traffic damage costs and these values and costs are assumed to differ for the various sex and age classes of red deer. We show that the maximum harvest strategy leads to a reasonably high positive total net benefit, while the free harvest strategy yields a small positive net benefit. On the other hand, the trophy hunting strategy generates a high negative net benefit, while small negative net benefits are obtained under the two strategies for natural demographic population compositions.

Impact of population aging and declining birth rates on household consumption structure: Evidence from China

The age structure of a population is a crucial indicator of a country's economic development. This study analyzes the impact of population aging and declining birth rates on the household consumption structure in urban and rural China. China, the largest country by population, is selected owing to its significance in population studies. Using a fixed effects model, our findings reveal that in China, a higher proportion of youth in the population positively affects residents’ spending on survival consumption while negatively affecting developmental consumption. Conversely, a higher proportion of older adults in the population negatively affects survival consumption while positively influencing developmental consumption.Through the research in this article, it is hoped that the results can provide some reference significance for the changes in population age structure and the development of resident consumption.

Mathematical Analysis of an Age-Structured Population Model with Nonlocal Diffusion and Distributed Delay

Mathematical Analysis of an Age-Structured Population Model with Nonlocal Diffusion and Distributed Delay

Dynamics of an age-structured tumor cell population model with nutrition

Dynamics of an age-structured tumor cell population model with nutrition

Demographic regulation processes in Pinna nobilis population subunits: Implications for restocking

A mass mortality event (MME) affected the endemic bivalve Pinna nobilis across the Mediterranean Sea in autumn 2016. This event affected specimens of all sizes, depth ranges and habitat types, resulting in a drastic decline in the species population close to 100%. Indeed, the consequences of a potential recovery, and therefore the viability of the populations of the species are unknown. To evaluate the likelihood of success when designing the reintroduction of the species in optimal areas, knowledge of population dynamics is essential. Here we compare two population subunits of Pinna nobilis from two areas with different environmental conditions, located in Cabrera National Park (protected area with low exposure to hydrodynamic activity) and San Telmo (unprotected area exposed to hydrodynamic activity), both in the Balearic Islands. A total of 259 individuals were tagged and monitored annually between 2011 and 2014, prior to the MME. Matrix population models were used to reduce the complexity of the age-structured population dynamics and assessing the degree of elasticity of the population. We showed that the subunit of San Telmo showed highly variable values of demographic rates, higher stochasticity and higher sensitivity to environmental variability than the population subunit of Cabrera National Park. The study shows the importance of the buffering effect of a large population as there are many adult individuals of many size classes in the population subunit of Cabrera National Park, as its age structure helps to cope with highly variable reproductive success. Therefore, these population subunits are more stable regardless of depth and would be a more suitable site for future reintroduction programs.

Aging, low fertility and household debt risk

Population aging is a typical feature of the change of population age structure in many developed countries at present, and the resulting family economic burden is an important factor causing debt risk. This paper uses the sample data of 33 economies of the Bank for International Settlements (BIS) from 1992 to 2021 to study the impact of population age structure on household debt risk and its mechanism. The study found that: First, The rising proportion of the elderly population and the elderly dependency ratio have significantly increased the household debt levels, Population aging can increase the risk of household debt by affecting the pension level, total factor productivity and worker share; second, After the economy has suffered from economic fluctuations, The impact of population aging on household debt risk has changed from nonsignificant to positively significant, Show that the economic crisis has reduced household income levels, It weakens the family's solvency; third, With the relatively sound social security system in developed economies, Higher levels of national income, As a result, the aging population has a weak effect on household debt risk. Fourth, human capital investment can alleviate the negative impact of population aging to a certain extent. The reason is that the improvement of education level will improve the living conditions of families and enhance residents' awareness of independent old-age security. The conclusions of this paper have important policy implications for deeply exploring the social consequences of aging economy and reasonably YESling the spillover of household debt risk.

Cumulative excess deaths in New Zealand in the COVID-19 era: biases from ignoring changes in population growth rates: comment

For measuring mortality and excess deaths, age standardised mortality has been an industry standard for centuries. Methods that acknowledge changes in population age structure should be used when assessing mortality.

Характеристики демографічної резильєнтності населення України у період пандемії Covid-19

The full-scale military invasion of Ukraine by the Russian Federation came at a time when our country had been weakened by a series of shocks in a relatively short historical period. Shocks such as a prolonged pandemic and war can disrupt and, in some cases, halt demographic development. In this context, the study of demographic resilience on the eve of a full-scale war, which became a new powerful shock for Ukraine, is relevant and necessary. The complexity of this issue does not allow us to provide all the answers in one article. The purpose of our paper is to determine the main parameters of the demographic resilience of the population of Ukraine in the Covid-19 period and to compare them with the characteristics of resilience in other periods of the greatest shocks experienced by our country, as well as with the indicators of other countries. In our study the main indicators of transient dynamics (convergence time, reactivity, population inertia, damping ratio) were calculated for the first time for the population of Ukraine. The influence of the contribution of different age groups of women to total fertility on the age structure of the population (with the same total fertility rate) was also determined for the first time. The calculations were based on the stable population model, the Leslie matrix, fertility tables, and life tables. The resilience indicators were calculated using the popdemo package. Methods of comparison, generalisation, and analogy were also used. Among the characteristics of demographic resilience, the half-life indicator stands out for its simplicity of calculation and interpretation. In Ukraine, the halving time for the population is decreasing, but it is still higher for the real population than for its stable equivalent. The age structure of the real population, formed under more favourable conditions, mitigates the negative consequences of shock periods, but the long-term preservation of the current regime of mortality and fertility will inevitably worsen the characteristics of the population. In Ukraine, advanced motherhood is an element of the adaptive cycle and requires a rethinking of its meaning and role, as it can be one of the internal mechanisms aimed at the resilience of the system in shock periods. In the conditions of the lowest-low fertility and mortality regime in Ukraine in 2021, advanced maternal age contributed to some increase in the number of births and a certain rejuvenation of the age structure of the population.