A Demographic Analysis of the Rise in the Prevalence of the US Population Overweight and/or Obese

Using data from the National Health Interview Survey for years spanning 1976 and 2001, this paper presents an age–period–cohort analysis of weight gain throughout the life cycle. We find that while all ages experienced an increase in the prevalence of those overweight and/or obese, the prevalence among young adults has grown at a faster rate than that of older age groups. The increases in body mass index are primarily due to period effects, not cohort or age effects. From the ordered logistical regression analyses, we find that the protective influence of factors such as education, income, and age on an individual’s body mass index have decreased over time. The analyses suggest that the increase in the prevalence of those overweight or obese is a phenomenon experienced by all demographic groups in the US, albeit to differing degrees.

The effects of race,ethnicity, and age on obesity

About 30% of Americans are obese, which is roughly a 100% increase from 25 years ago. This study examines the effects of changes in the racial/ethnic composition and age distribution on the prevalence of obesity, identifies the portion of the increase in obesity caused by these changes, and projects the effects of future racial/ethnic and age changes on obesity using National Health and Nutrition Examination Survey data. Results indicate that racial/ethnic composition changes and age distribution changes have accounted for about 10% of the increase in obesity over the last 25 years. However, future racial/ethnic and age changes are not projected to increase obesity substantially.      

U.S. population in the 21st century: Which scenario is reasonable?

A major Census Bureau study released in January 1989 has evoked renewed warnings in the media and among some population analysts that the U.S. faces population decline in the next century if it does not increase fertility and/or raise immigration. The report's middle scenario rests on an assumed future total fertility rate (TFR) of 1.8, life expectancy of 81.2 years, and net immigration of 500,000 annually. These mid-range assumptions would yield a United States population of 268 million by 2000, peaking at 302 million in 2040 and falling to 292 million by 2080. Questionable assumptions in the report's most likely scenario are discussed. These are:

1. that immigrants bear children at the same rate as their equivalent age and racial group in the United States population.
2. that the high TFR of Hispanics will not raise the overall 1.8 TFR foreseen for whites as the Hispanic proportion of the white population continues to grow.
3. that net yearly immigration will fall to 575,000 in 1990 and 500,000 by 2000. The Census Bureau's "high" assumption of 800,000 net yearly may be more realistic.

The report's low growth scenario projects future population size that is more reassuring than alarming: 264 million in 2000, rising to 288 million in 2030, and falling to 266 million in 2080. Thus, in ninety years the United States would still have 20 million more people than now. While some fear that such slow growth will lower United States influence and bring labor shortages and an aging population, the nation's quality of life would be less at risk with a population of 266 million than with one approaching the one-half billion projected by the Census report's high estimates.     

中国少数民族人口发展形势分析

一、人口数量 20世纪80年代,中国少数民族人口一度高速增长,从1982年的6643万人增至1990年的9057万人,年均增长率达到3．89％,占全国人口的比例从6．62％提高到8．01％。1990—2000年,根据“五普”资料,全国（大陆）人口增加了9．92％,其中,汉族人口由103919万人增至113739万人,增加了9．45％,全国人口和汉族人口年均增长率分别为0．91％和0．87％;     

What Data from the 2010 Census Tell Us about the Changing Child Population of the United States

This article provides an overview of changes in the U.S. child population (persons under age 18) based on data released from the 2010 census. Today, the number of children in the United States (74.2 million) is at an all-time high, but the share of the national population who are children (24 %) is at an all-time low. The number of children in the population grew by 1.9 million between 2000 and 2010, but the overall national figure masks many important details and divergent paths. The growing racial and ethnic diversity in the U.S. is more advanced among children than among adults. Some areas of the country and some demographic groups grew significantly over the decade, while the number of children in other areas and in other groups fell.     

America’s Churning Races: Race and Ethnicity Response Changes Between Census 2000 and the 2010 Census

A person’s racial or ethnic self-identification can change over time and across contexts, which is a component of population change not usually considered in studies that use race and ethnicity as variables. To facilitate incorporation of this aspect of population change, we show patterns and directions of individual-level race and Hispanic response change throughout the United States and among all federally recognized race/ethnic groups. We use internal U.S. Census Bureau data from the 2000 and 2010 censuses in which responses have been linked at the individual level (N = 162 million). Approximately 9.8 million people (6.1 %) in our data have a different race and/or Hispanic-origin response in 2010 than they did in 2000. Race response change was especially common among those reported as American Indian, Alaska Native, Native Hawaiian, Other Pacific Islander, in a multiple-race response group, or Hispanic. People reported as non-Hispanic white, black, or Asian in 2000 usually had the same response in 2010 (3 %, 6 %, and 9 % of responses changed, respectively). Hispanic/non-Hispanic ethnicity responses were also usually consistent (13 % and 1 %, respectively, changed). We found a variety of response change patterns, which we detail. In many race/Hispanic response groups, we see population churn in the form of large countervailing flows of response changes that are hidden in cross-sectional data. We find that response changes happen across ages, sexes, regions, and response modes, with interesting variation across racial/ethnic categories. Researchers should address the implications of race and Hispanic-origin response change when designing analyses and interpreting results.     

An overview of the geographic distribution of the population in China]

China is the nation which has the earliest record of its population. During its history of 4000 years, China's population remained between 10 million and 20 million for the 1st 2000 years. In the Han dynasty, the figure increased to 59 million. At the beginning of 17th century, the population decreased to between 10 million and 20 million because of war and social disorders. In the middle of the 18th century, the total population figure reached 100 million for the 1st time. At the end of the 18th century, it reached 300 million, and at the beginning of 20th century, it increased to 400 million. By 1980, the total population figure had increased to 1 billion. Before the Han dynasty, the Chinese population was mainly distributed in North China along the Yellow River. After the Period of Three Kingdoms (420-589 A.D.), more Chinese moved to South China along the Yangtze River. During the Five Dynasties (907-960 A.D.), the population ratio between the South and the North changed to 3 to 1, and this ratio has been maintained since then. A great majority of the Chinese population is engaged in agriculture and lives in the countryside. China is a nation with many ethnic groups. Of the total population, 94% are Han people, and 6% are minorities which belong to 55 ethnic groups. There are also 5 language families in China, with the Han language being the most popular. About 96.31% of the Chinese population is distributed in the eastern half of the country, and only 3.69% are distributed in the southwest, northwest, and northern frontiers. The highest population density is concentrated in the lower Yellow River and Yangtze River areas.     

An Optimum Population for North and Latin America

The population of North America, which now stands at nearly 300 million people, is projected to double in about 60 years, while the population of nearly 500 million people in South America is projected to double in less than 40 years. Both of these populations obtain more than 99% of their food from the land, and this percentage will increase as these populations grow. Maintaining fertile and ample land is critical if these large populations are to be fed. Soil degradation by soil erosion is a serious problem on both continents. In addition, agricultural land is being lost to urbanization and highways because of rapid population growth. Nearly a half hectare of land is needed for urbanization for each person added to the North American population; this is already causing serious problems with agriculture in some states in the United States. The land resources that are critical for food production will be especially so if the populations of both continents double to nearly 2 billion. Land resources will also be critical when both continents deplete their fossil fuels in less than 100 years and have to turn to renewable energy sources. With about 2 billion people, there will be serious shortages of food, water, and energy resources and the standard of living will significantly decline. Our assessment suggests that for a relatively high standard of living in North and South America each continent should have no more than about 200 million people, or a total of 400 million.     

The outlook of China's population after the stabilization of birth policy

A professor of the Institute of Population Research of the People's University of China attempts to project the future population development of China so that stabilization of the birth policy can be assessed. He divides China into the economically developed and population-controlled area (29% of the population), the economically subdeveloped and population fairly-controlled areas (59% of the population), and the economically less-developed areas where fertility is high (12% of the population). China's population is expected to increase because of the baby boom to 1.25-1.3 billion by the year 2000. Between 1996 and 2000, the growth rate is expected to decelerate and reach zero growth. After 2010, if growth is held at the replacement rate of 2.1, the population will still continue to grow slowly. Around 2100, China's population should be around 1.45-1.59 billion. This would cause a decrease of 27% of arable land. With a decline in fertility rate comes a rise in the amount of the aged population (4.9% in 1982 vs. 5.5% in 1987). The proportion of aged citizens is expected to rise with the stabilization policy until around 2040 where it can be held at about 18%. China's GNP by the year 2000 is expected to be US$1183.8 billion with the per capita GNP about US$934 (providing the population is controlled). Compare this figure with the per capita GNP of the world (US$30,100) and of developed countries (US$10,700) in 1988, and one can see that China is far behind the rest of the world in economic growth.     

Ethnic population projections for the UK, 2001–2051

This paper reports on projections of the United Kingdom’s ethnic group populations for 2001–2051. For the years 2001–2007 we estimate fertility rates, survival probabilities, internal migration probabilities and international migration flows for 16 ethnic groups and 355 UK areas. We make assumptions about future component rates, probabilities and flows and feed these into our projection model. This model is a cohort-component model specified for single years of age to 100+. To handle this large state space, we employed a bi-regional model. We implement four projections: (1) a benchmark projection that uses the component inputs for 2001; (2) a trend projection where assumptions beyond 2007 are adjusted to those in the UK 2008-based National Population Projections (NPP); (3) a projection that modifies the NPP assumptions and (4) a projection that uses a different emigration assumption. The projected UK population ranges between a low of 63 millions in 2051 under the first projection to a high of 79 million in the third projection. Under all projections ethnic composition continues to change: the White British, White Irish and Black Caribbean groups experience the slowest growth and lose population share; the Other White and Mixed groups to experience relative increases in share; South Asian groups grow strongly as do the Chinese and Other Ethnic groups. The ethnic minority share of the population increases from 13% (2001) to 25% in the trend projection but to only 20% under our modified emigration projection. However, what is certain is that the UK can look forward to be becoming a more diverse nation by mid-century.     

The Changing Racial and Ethnic Composition of the US Population: Emerging American Identities

Images and interpretations of the past, present, and future of the American racial and ethnic landscape are contradictory. Many accounts focus on the increasing diversity that results from immigration and differential natural increase as well as the proliferation of racial and ethnic categories in census data. Less attention has been paid to the formation and erosion of racial and ethnic identities produced by intermarriage and ethnic blending. The framers and custodians of census racial classifications assume a “geographic origins” definition of race and ethnicity, but the de facto measures in censuses and social surveys rely on folk categories that vary over time and are influenced by administrative practices and sociopolitical movements. We illustrate these issues through an in‐depth examination of the racial and ethnic reporting by whites, blacks, Asians, and Hispanics in the 2000 census. The emerging pattern, labeled here as the “Americanization” of racial and ethnic identities, and most evident for whites and blacks, is of simplified racial identities with little acknowledgment of complex ancestries. National origin is the predominant mode of reporting racial and ethnic identities among Asians and Hispanics, especially first‐generation immigrants. The future of racial and ethnic identities is unknowable, but continued high levels of immigration, intermarriage, and social mobility are likely to blur contemporary divisions and boundaries.     

Understanding the demographic implications of climate change: estimates of localized population predictions under future scenarios of sea-level rise

Significant advances have been made to understand the interrelationship between humans and the environment in recent years, yet research has not produced useful localized estimates that link population forecasts to environmental change. Coarse, static population estimates that have little information on projected growth or spatial variability mask substantial impacts of environmental change on especially vulnerable populations. We estimate that 20 million people in the United States will be affected by sea-level rise by 2030 in selected regions that represent a range of sociodemographic characteristics and corresponding risks of vulnerability. Our results show that the impact of sea-level rise extends beyond the directly impacted counties due to migration networks that link inland and coastal areas and their populations. Substantial rates of population growth and migration are serious considerations for developing mitigation, adaptation, and planning strategies, and for future research on the social, demographic, and political dimensions of climate change.     

Social Networks and Support,Gender, and Racial/Ethnic Disparities in Hypertension Among Older Adults

Using data from the 2001 NHIS and the 2005–2006 and 2007–2008 NHANES, we examine how self-reporting a previous diagnosis of hypertension among adults aged 65+ differs by race/ethnicity for men and women; we explore the extent to which disparities are driven by group differences in social risk factors, particularly social support and integration; and last, whether these relationships mimic patterns seen for measured hypertension at interview. Findings indicate that rates of ever-diagnosed hypertension in both samples are highest among black seniors and older women and lowest among Mexican-American men, with the gender gap lowest among whites and substantially higher among blacks and Mexican-Americans. However, replication analyses of NHANES models using measured hypertension, instead of a self-report of having ever been diagnosed with hypertension, suggests that reporting bias and measurement error contribute to observed disparities, as racial/ethnic differences in hypertension rates are smaller when measured hypertension is examined, especially among women. Logistic regression models also show that while adjusting for group differences in measures of support and integration mediates some of the disparity in measured hypertension between Mexican-American and white seniors, adjusting for support and integration amplifies black-white disparities in both ever diagnosed and measured hypertension—driven primarily by adjustment for attendance at religious services, which reduces hypertension risk for all older adults but is more commonly reported among black seniors, especially women.     

Who are American Indians? Some observations about the perils and pitfalls of data for race and ethnicity

The data for race and ethnicity published from the 1980 Census are based on racial and ethnic self-identification of respondents. Selfidentification of race and ethnicity is problematic mainly because analysts are frequently inclined to treat this information as immutable. However, as this paper suggests, for some groups such as American Indians, racial and ethnic identity is an extremely complex phenomenon which has the potential to be highly variable. American Indians present an ideal case to demonstrate the possible problems facing analysts who do not recognize the potentially variable meanings of race and ethnicity data. This paper shows that, depending on how American Indians are defined, population estimates can range from less than 1.0 million to nearly 7.0 million. Furthermore, it is possible to isolate three types of American Indian identities in 1980 Census data, and each of these groups have different socioeconomic profiles.     

World population beyond six billion

This world report reviews population growth pre-1900, population change during 1900-50 and 1950-2000, causes and effects of population change and projections to 2050. World population grew from 2 billion in 1900 to almost 6 billion in 2000. Population showed more rapid growth in the 17th and 18th centuries. Better hygiene and public sanitation in the 19th century led to expanded life expectancies and quicker growth, primarily in developed countries. Demographic transition in the 19th and 20th centuries was the result of shifts from high to low mortality and fertility. The pace of change varies with culture, level of economic development, and other factors. Not all countries follow the same path of change. The reproductive revolution in the mid-20th century and modern contraception led to greater individual control of fertility and the potential for rapid fertility decline. Political and cultural barriers that limit access affect the pace of decline. Population change is also affected by migration. Migration has the largest effect on the distribution of population. Bongaarts explains differences in fertility by the proportion in unions, contraceptive prevalence, infertility, and abortion. Educational status has a strong impact on adoption of family planning. Poverty is associated with multiple risks. In 2050, population could reach 10.7 billion or remain low at 7.3 billion.     

人口增长率与人口规模关系的实证研究——基于中国省际面板数据的分析

文章在内生经济理论的框架下推导了在一定条件下人口增长率与人口规模负相关的结论,同时基于1954年至2007年的数据,运用动态面板数据模型验证了人口增长率与人口规模负相关。文章的动态面板协整检验表明,我国人口规模每增加一亿,人口增长率将减少2.13‰,我国人口规模将会达到15.4亿的峰值,然后人口增长率出现负增长。最后文章的格兰杰因果检验也表明,人口规模的变化是人口增长率变化的格兰杰原因。     

Communique of the State Family Planning Commission on a nationwide fertility sampling survey of every person per thousand

In 1982, the Chinese State Family Planning Commission conducted a nationwide fertility survey of 1 person/1000 in 28 provinces, municipalities, and autonomous regions. 815 sample units were selected and 310,462 women aged 15-67 were interviewed, 99.9% of those identified. 252,094 (24.77%) were of childbearing age (15-49) with 24.76% 15-19 years old. Among women of fertile age, 31.46% were unmarried, 64.53% were married to their 1st husbands, 2.89% were remarried, .19% were divorced, and .94% were widowed. Average age of 1st marriage increased from 18.4 in the 1940s to 22.8 in 1981. Total fertility rate dropped from 5.44 in the 1940s to 2.63 in 1981. In 1981, the birth rate was 85/1000 women of fertile age. Fertility was much higher among minority nationalities. 118 million of China's 170 million married couples of reproductive age (69.46%) use birth control at present; 50.2% use the IUD, 25.4% tubal ligation, 10.0% vasectomy, 8.2% oral contraceptives, and 2.0% condoms. About 21 million married women should have begun using contraception but have not. 14 million or 42.3% of 33 million 1 child couples have pledged to have only 1 child. If the fertility level of 1981 is maintained and the average woman continues to have 2.63 children, 2.91 in rural areas, China's population will reach 1.2 billion by 1993 and will exceed 1.3 billion by 2000. The Central Committee has a target population of 1.2 billion by 2000.     

Our population predicament: a new look

Issued to mark the Population Reference Bureau's 50th anniversary, this issue updates the story of world population presented in its popular predecessor of 1971, "Man's Population Predicament." Estimated at 1/2 billion in 1650, world population reached about 2 billion in 1930, 4 billion in 1975, and is projected to be about 6 billion in 2000. Most of today's rapid growth is occurring among the 3/4 of the world's peoples living in less developed countries where the post-World War II gap between high birth rates and falling death rates has only recently begun to narrow. This growth, coupled with high consumption in developing countries, is putting tremendous pressures on the Earth's resources, environment, and social fabric. New evidence on Europe's population transition and from China, Indonesia, and Thailand in the 1970s suggests that well-designed family planning programs can speed fertility decline but rapid worldwide attainment of replacement level fertility will also require special development efforts and measures that go beyond family planning. Current projections of the world's ultimate peak population range from 8 billion in the mid 21st century to 11 billion in about 2125, depending on when replacement-level fertility is reached. China's drive for a drastic birth rate reduction and the oil crisis might change fertility behavior more rapidly than most demographers have heretofore thought likely.     

A decomaosition of trends in poverty among children of immigrants

Poverty levels among all children in the United States have tended to fluctuate in the past 30 years. However, among the children of immigrants, child poverty increased steadily and rapidly from about 12% in 1970 to 33% in the late 1990s before declining to about 21% in 2000. Using 1970, 1980, 1990, and 2000 Public Use Microdata Samples data, we identified key factors that underlie the fluctuations in immigrant child poverty from 1969 to 1999 and the divergence from children of natives. We found that roughly half the absolute increase in immigrant child poverty can be linked to changing conditions in the U.S. economy that make it more difficult to lift a family out of poverty than 30 years ago. These changes occurred disproportionately among children of parents with lower levels of education, employment, and U.S. experience but not among racial/ethnic minorities. Poverty risks among various racial and ethnic groups converged over time. The relative increase in poverty for immigrant versus native children owes largely to the divergence between immigrant and native families in racial/ethnic composition, parental education, and employment.     

The fertility contribution of Mexican immigration to the United States

Crucial to the long-term contribution of immigration to a receiving country's population is the extent to which the immigrants reproduce themselves in subsequent, native-born generations. Using conventional projection methodologies, this fertility contribution may be poorly estimated primarily because of problems in projecting the number of immigrants who are at risk of childbearing. We propose an alternative method that obviates the need to project the number of immigrants by using the full sending-country birth cohort as the risk group to project their receiving-country childbearing. This "sending-country birth cohort" method is found to perform dramatically better than conventional methods when projecting to 1999 from base years both before and after the large increase in inflows of Mexican immigrants to the United States in the late 1980s. Projecting forward from 1999, we estimate a cumulative contribution of Mexican immigrant fertility from the 1980s to 2040 of 36 million births, including 25% to 50% more births after 1995 than are projected using conventional methods.