Immigration and the dependency ratio of a host population

This paper examines the long-term impact of constant immigration on the dependency ratio in an SI population (a stationary population through constant immigration) in the context of the stable population model. Our analysis has three main findings. First, in SI populations, a younger population (a lower aging ratio) does not necessarily have a lower dependency ratio. An SI population has a lower dependency ratio than a closed stationary population, provided immigration is concentrated around the youngest working age in the host population. Second, under the same condition, selecting high-fertility immigrants increases the dependency ratio. Third, also under the same condition, substituting working-age immigrants with young (dependent) immigrants increases the dependency ratio. Using the United Nations model age structures of immigrants, our empirical illustration confirms these analytical results.     

An age‐structured model of population dynamics with dominant ages,delayed behavior,and oscillations

An age‐structured model of population dynamics with age‐dominance is proposed and analyzed. Existence and uniqueness of solutions are established as well as the uniqueness and local asymptotic stability of steady‐states. Conditions for convergence to or oscillation about the steady‐state are specified in some cases.     

A special section for correspondence and controversy

Summary The programs described above cost the state about $1 billion. Other state costs (which are not my responsibility) are incarceration costs for illegals, $400 million. Education cost for children of illegals has been estimated to be $1.7 billion this year. These two alone equal $2.1 billion.Please accept my assurances, and those of Governor Wilson, that we in the administration are not xenophobic or nativistic.I do not know if 8.6 million persons is a reasonable number for our nation of 250 million plus to accept and assimilate. I am convinced that 4.3 million is too many for a single state of 30 million to assimilate effectively. Certainly the costs of doing so are beyond our capacity to absorb without help.I am convinced that our existing assimilation ability is hamstrung by federal practice that ignores our immigration laws by permitting an unchecked flow of illegal immigrants into our country. Over half of this population enters and resides in California.The problem is exacerbated by the almost total failure of the federal government to support itslegal immigration decisions with federal funds to offset the costs of the resultant influx of immigrants.Presented at the Pacific Research Institute Conference on immigration, San Francisco, CA, April 25, 1994.     

Life expectancy, fertility, and educational investment

In this study, we develop a model of overlapping generations where adults make decisions on consumption, fertility, and their personal education. We show that under the assumption of exogenous mortality, there are multiple steady states with club convergence occurring when mortality is sufficiently high. If mortality is sufficiently low, there will be a unique, stable steady state, and the economy will converge to a “good” steady state irrespective of where it starts from. Under the assumption of endogenous mortality with “threshold effects,” we find that club convergence will occur if the threshold is sufficiently high; conversely, a low threshold can help the economy to steer clear of the underdevelopment trap.     

Momentum and the growth-free segment of a population

In the scenario of a sudden drop in fertility to replacement level. Preston (1986) argued that the population segment under age T, the length of generation, remained growth-free. Here we first present a new relationship for the momentum of any observed population as the ratio of 1) the proportion of the observed population under the mean age at childbearing to 2) the proportion of its life table population under that mean age. We then use that relationship to demonstrate Preston's approximation. Growth factors for other population segments are also presented. When the initial population is stable, momentum can be approximated as a function of the net reproduction rate alone.     

Fate of a mutant emerging at the initial stage of evolution

A simple system was constructed and used in the experimental elucidation of the fate of a mutant emerging in a population. ThreeEscherichia coli strains having the same genetic background except for their glutamine synthetase gene were used as model competitors. The difference in the enzyme gene were introduced by random mutation. Competition between these bacterial strains was carried out and observed in a continuous liquid culture. In most cases, the competitors stably coexist either in a steady state or in an oscillating state. In addition, the competition between the strains was found to be a deterministic process and not a stochastic one. These results showed that an emerging mutant in a population, be it a closely related one to the original members, can attain a state of stable coexistence even in a homogeneous environment. The ability of each of the emerging mutants to maintain its stable coexistence with the original population gives rise to the accumulation of various mutants in a population. Therefore, evolution starts from gradual accumulation of various mutants in the population, which in turn leads to the diversification of the population. As our experimental system is a minimum model for the various competitions in the natural ecosystem, the observed competitive coexistence is proposed to be a general phenomenon in nature.     

The fiscal impact of immigration to welfare states of the Scandinavian type

In this paper, we examine the potential of immigration to strengthen fiscal sustainability, which is under pressure by an ageing population in many European countries. We look at a particularly challenging case, namely that of Denmark, which has extensive tax-financed welfare programmes that provide a high social safety net. The analysis is based on a forecast of the entire Danish economy made using a dynamic computable general equilibrium model with overlapping generations. We present life cycle estimates of the potential fiscal impact of immigration considering the cost of immigration on the margin as well as on average. The main conclusion is that immigrants from Western countries have a positive fiscal impact, while immigrants from non-Western countries have a large negative one, which is also the case when considering only non-refugee immigrants. The negative effect is caused by both a weak labour market performance and early retirement in combination with the universal Danish welfare schemes.     

中国人口年龄结构特征与变化趋势分析--基于1995～2014年数据的实证研究

人口年龄结构是经过多年人口自然增长和迁移变动等综合作用而形成的客观状况,对未来人口发展的速度和趋势以及国家或地区经济社会整体发展产生重要影响。本文通过对1995～2014年数据的实证分析,发现20年来我国人口年龄结构呈现以下特征：少儿人口数量减少且比重呈持续下降趋势;劳动年龄人口数量稳步增长且比重呈稳定上升趋势;老年人口数量持续增长且比重呈上升趋势,老龄化进程加快。总体人口年龄结构呈现老年型,各地区人口老龄化程度存在差异。各地人口负担系数存在较大差异,人均GDP与总抚养比和少年儿童抚养比呈负相关,与老年人口抚养比呈正相关。经济发达省市区人口负担系数较小;城乡人口比例呈持续升高态势;城乡人口总抚养比和少儿抚养比呈下降趋势,城乡老年人口抚养比呈稳步升高态势;乡村人口抚养比高于城镇。     

The UN Population Division on Replacement Migration

The most salient demographic trend pictured by the influential set of population projections prepared by the Population Division of the United Nations (a unit in the UN's Department of Economic and Social Affairs) is the continuing substantial increase—albeit at a declining rate—of the global population during the coming decades. According to the “medium” variant of the most recent (1998) revision of these projections, between 2000 and 2050 the expected net addition to the size of the world population will be some 2.85 billion, a figure larger than that of the total world population as recently as the mid‐1950s. All of this increase will occur in the countries currently classified as less developed; in fact, as a result of their anticipated persistent below‐replacement levels of fertility, the more developed regions as a whole would experience declining population size beginning about 2020, and would register a net population loss of some 33 million between 2000 and 2050. A report prepared by the UN Population Division and released on 21 March 2000 addresses some of the implications of the changes in population size and age structure that low‐fertility countries will be likely to experience. The 143‐page report, issued under the eyecatching title Replacement Migration: Is It a Solution to Declining and Ageing Populations?, highlights the expected magnitude of these changes by the imaginative device of answering three hypothetical questions. The answer to each of these questions is predicated on the assumption that some specified demographic feature of various country or regional populations would be maintained at the highest level that feature would exhibit, in the absence of international migration, in the United Nations' medium population projections (as revised in 1998) during the period 1995–2050. The selected demographic features are total population size, the size of the working‐age population (15–64 years), and the so‐called potential support ratio: the ratio of the working‐age population to the old‐age population (65 years and older). The illustrative device chosen for accomplishing the specified feats of preserving the selected demographic parameters (i.e., keeping them unchanged up to 2050 once their highest value is attained) is international migration. Hence the term “replacement migration.” Given the low levels of fertility and mortality now prevailing in the more developed world (and specifically in the eight countries and the two overlapping regions for which the numerical answers to the above questions are presented in the report), and given the expected future evolution of fertility and mortality incorporated in the UN population projections, the results are predictably startling. The magnitudes of the requisite compensatory migration streams tend to be huge relative both to current net inmigration flows and to the size of the receiving populations; least so in the case of the migration needed to maintain total population size and most so in the case of migration needed to counterbalance population aging by maintaining the support ratio. Reflecting its relatively high fertility and its past and current record of receiving a large influx of international migrants, the United States is a partial exception to this rule. But even for the US to maintain the support ratio at its highest—year 1995—level of 5.21 would require increasing net inmigration more than tenfold. The country, the report states, would have to receive 593 million immigrants between 1995 and 2050, or a yearly average of 10.8 million. The extreme case is the Republic of Korea, where the exercise calls for maintaining a support ratio of 12.6. To satisfy this requirement, Korea, with a current population of some 47 million, would need 5.1 billion immigrants between 1995 and 2050, or an average of 94 million immigrants per year. (In the calculations, the age and sex distribution of migrants is assumed to be the same as that observed in the past in the main immigration countries. The fertility and mortality of immigrants are assumed to be identical with those of the receiving population.) The “Executive Summary” of the report is reproduced below, with the permission of the United Nations. Chapters of the full report set out the issues that prompted the exercise; provide a selective review of the literature; explain the methodology and the assumptions underlying the calculations; and present the detailed results for the eight countries and two regions selected for illustrative purposes. A brief discussion of the implications of the findings concludes the report. As is evident even from the figures just cited, immigration is shown to be at best a modest potential palliative to whatever problems declining population size and population aging are likely to pose to low‐fertility countries. The calculations, however, vividly illustrate that demographic changes will profoundly affect society and the economy, and will require adjustments that remain inadequately appreciated and assessed. The criteria specified in the UN calculations—maintenance of particular demographic parameters at a peak value—of course do not necessarily have special normative significance. Past demographic changes, with respect notably to the age distribution as well as population size, have been substantial, yet they have been successfully accommodated under circumstances of growing prosperity in many countries. But the past may be an imperfect guide in confronting the evolving dynamics of low‐fertility populations. As the report convincingly states, the new demographic challenges will require comprehensive reassessments of many established economic and social policies and programs.     

Empirical characteristics of legal and illegal immigrants in the USA

We combine the New Immigrant Survey (NIS), which contains information on US legal immigrants, with the American Community Survey (ACS), which contains information on legal and illegal immigrants to the USA. Using an econometric methodology proposed by Lancaster and Imbens (J Econ 71:145–160, 1996) we compute the probability for each observation in the ACS data to refer to an illegal immigrant, conditional on observed characteristics. These results are novel, since no other work has quantified the characteristics of illegal immigrants from a random sample representative of the population. Using these conditional probability weights on the ACS data, we are able to uncover some interesting facts on illegal immigrants. We find that, while illegal immigrants suffer a large wage penalty compared to legal immigrants at all education levels, the penalty decreases with education. We also find that the total fertility rate among illegal immigrant women is significantly higher than that among legal ones, in particular for middle and higher educated women. Looking at the sector of activity, we document that the sectors attracting most illegal immigrants are constructions and agriculture. We also generate empirical distributions for state of residence, country of origin, age, sex, and number of legal and illegal immigrants. Our forecasts for the aggregate distribution of legal and illegal characteristics match imputations by the Department of Homeland Security.     

Demographic Change and Immigration in Age-structured Epidemic Models

Immigration might be a remedy against the stress that low fertility causes to demographic and welfare systems. Sustained immigration, however, can alter both the demographic and epidemiological profiles of the receiving population. An age-structured SIR (susceptible-infective-recovered) model with realistic immigration under conditions of below replacement fertility is studied. Equilibria and threshold phenomena are characterized. The immigration profile and the epidemiological features of immigrants affect the reproduction number and the force of infection in the receiving population. Finally, an illustration is given, showing the potential effects of immigration for rubella control in Italy, by considering how the age profile of immigration influences the reproduction number of the disease.     

The effect of immigration on the internal migration of the native-born population, 1981–1990

This study examines the impact of immigration on the labor market opportunities of the native-born population by looking through the window of migration. We use Current Population Survey data to analyze the one-year migration patterns of Anglos and Blacks and include the presence of recent immigrants in the origin and (potential) destination US states among the covariates. Our departure model employs a logit specification to predict outmigration (vs not) from the state during the year prior to the survey. Our arrival model uses a conditional logit discrete choice specification with sampling among the alternatives to predict destination state. The data are taken from the 1981, 1984, 1987, and 1990 Current Population Surveys. This work adds to other knowledge of the migratory response of workers and sheds light on theories of substitution and complementarity in labor markets. States with high levels of recent immigration are less likely to retain Anglo workers or receive new Anglo interstate migrants, but this apparent substitution effect is partially offset by the presence of long-term immigrant stock. Lower skilled Anglos are more susceptible to this substitution effect than those of higher skill level. In the black population, results are more complex. Lower skilled blacks are less attracted to high immigrant locations, but African-Americans of higher skill level in selected occupations and industries are predicted to be more likely to remain in or choose states with many recent immigrants.     

Population dynamics of the whitebacked planthopper,Sogatella furcifera (Hemiptera: Delphacidae) with special reference to the relationship between its population growth and the growth stage of rice plants

A population census was conducted to describe the effects of the growth stage of rice on the population dynamics ofS. furcifera, in particular, on immigration, seasonal abundance, population growth rate, and wing-form expression. The number of immigrants was highest on rice plants 17 to 30 days after transplanting (DAT), which suggested that immigrants prefer to settle or remain more on rice plants at the tillering stage (approximately 20–30 DAT). Population growth rate from immigration to the 1st generation decreased with an increase in rice plant age. In contrast, population growth rate from the 1st to 2nd generation was not influenced by rice plant age and was negatively density-dependent. The percentage of macropters (flyers) was positively related to the growth stage of rice when rice was in the vegetative or early part of the reproductive stage, and reached 100% at about 10 days before heading (booting stage). Threafter, most adult females molted into macropters regardless of population density. The roles of host plant age and crowding effect on the population dynamics ofS. furcifera are discussed.     

成都市人口变动态势的预测及其含义

本文以“等维灰数递补动态模型”对“人口发展方程”的流动人口预测部分作了修正,从而构建大城市人口态势综合预测模型,并对成都市2005~2030年包括流动—迁移人口在内的总人口及其结构变动作了预测。本预测结果的一般性政策含义是,在维持现行低生育水平不变的前提下,人口年龄金字塔的内缩,人口结构全面深度老化的趋势不因人口流迁而改变。为此,作者提出了相应的对策思考。     

Presentation and establishment of a system of total progressive fertility rates and relevant models

Demographic studies necessarily rely on adequate and accurate statistical data. To take into consideration China's present situation of population control and planned birth practice, a system of total progressive fertility rate (TPFR) different from the parity progression ratio is established and its relevant model presented in order to make indicators used in analysing women's 1st marriage and fertility level reflect as closely as possible the actual situation. Here, TFR and TPFR, both used in analyzing fertility level, are compared so as to show that TPFR is a methodology more appropriate for use in the analysis of China's fertility. The model is based on the fact that women's vital events happen progressively from being born to completing childbearing. In composing the model, both women's age structure and parity structure are considered and the regularity of their changes with different years is defined. In China, the population development program has been brought into the overall social and economic development plan. Thus it is necessary to practice planned birth in order to make the population develop in a way which is in keeping with the social and economic development. Compared with other models or theories, it is more realistic to use the model discussed above in studies on China's population policy.     

人口年龄结构变动下的最优退休年龄动态模型构建与应用——以陕西省为例

文章主要以社会福利最大化为基本前提,假定社会福利最大化条件下的退休年龄为最优平均退休年龄,通过建立人口年龄结构变动下的最优退休年龄动态模型,以陕西省人口数据和养老保险相关数据为基础,测算了社会福利最大化条件下的陕西省最优平均退休年龄。得出结论:满足社会福利最大化时,陕西省最优平均退休年龄将会从2010年的58.4岁,逐步提高到2020年的59.6岁,进而提高到2030年的61.3岁。     

Smoking and Variation in the Hispanic Paradox: A Comparison of Low Birthweight Across 33 US States

The Hispanic Paradox in birth outcomes is well documented for the US as a whole, but little work has considered geographic variation underlying the national pattern. This inquiry is important given the rapid growth of the Hispanic population and its geographic dispersion. Using birth records data from 2014 through 2016, we document state variation in birthweight differentials between US-born white women and the three Hispanic populations with the largest numbers of births: US-born Mexican women, foreign-born Mexican women, and foreign-born Central and South American women. Our analyses reveal substantial geographic variation in Hispanic immigrant–white low-birthweight disparities. For example, Hispanic immigrants in Southeastern states and in some states from other regions have reduced risk of low birthweight relative to whites, consistent with a “Hispanic Paradox.” A significant portion of Hispanic immigrants’ birthweight advantage in these states is explained by lower rates of smoking relative to whites. However, Hispanic immigrants have higher rates of low birthweight in California and several other Western states. The different state patterns are largely driven by geographic variation in smoking among whites, rather than geographic differences in Hispanic immigrants’ birthweights. In contrast, US-born Mexicans generally have similar or slightly higher odds of low birthweight than whites across the US. Overall, we show that the Hispanic Paradox in birthweight varies quite dramatically by state, driven by geographic variation in low birthweight among whites associated with white smoking disparities across states.     

Dealing with omitted answers in a survey on social integration of immigrants in Italy

ABSTRACT

Surveys are used to infer the level of social integration of immigrants. Item response theory helps to describe the relationship among responses to test items and latent traits of interest. However, in the presence of nonignorable missing data, which are omitted responses depending on the latent traits to be measured, estimates of the model parameters are biased. To account for nonignorable missing data, the quantity and quality of contacts between immigrants and natives (so called “social integration”) are taken into account through a linear function of the response propensity. Higher education, no intention to migrate again, young age, Albanian nationality, and declaring a non-Muslim religion or none, comparatively favor social integration.     

Job Satisfaction Among Immigrant Workers: A Review of Determinants

In recent years, an increasing number of studies have investigated the well-being of international immigrants in host countries. An important indicator of immigrants’ well-being is job satisfaction. Job satisfaction reflects a pleasant emotional state, in which individuals positively appraise their job or work experience. In this article, we discuss the determinants of immigrants’ job satisfaction, based on research conducted over the past three and a half decades. The determinants observed in the literature can be categorized into work- and non-work-related groups. Work-specific determinants include workplace environments, job characteristics, and work-specific personal factors (e.g., competency-related factors, psychological states, and work-specific demographics). Non-work-specific determinants include general demographics, culture-related factors (e.g., language, cultural traits, and acculturation), and community-related factors. This review demonstrates that past research has made important strides toward our understanding of the influential factors leading to immigrants’ job satisfaction. We call for future research to continue to explore these factors, as well as new factors, given the limited empirical evidence that exists for this population group.