Bridging 1990 and 2000 census race data: Fractional assignment of multiracial populations

In contrast to previous censuses, Census 2000 permitted individuals to mark more than one race. Because the new race tables include both single-race and mixed-race categories, measuring change during the 1990s requires some method of bridging between the two data sets.To accomplish this bridging, we first identified biracial populations as of 1990 through the race and ancestry responses of individuals in the PUMS file. With race responses assumed to represent a person's primary race identity, we then determined the percentage of each biracial group that preferred each race as the primary identity. The same percentages can be used to assign biracial persons from Census 2000 into single-race categories. We also provide fractional assignment percentages for selected states and for the larger specific nationality groups of mixed-race Asians.Comparison of our 1990 estimates of the numbers in leading biracial groups with those reported in Census 2000 suggests that our fractional assignment values are reasonable for biracial groups other than those involving American Indians and Alaska Natives. For the latter biracial groups and for all groups representing three or more races, we recommend equal fractional assignment into the appropriate single-race categories.     

Quality and the 2010 Census

The U.S. Census Bureau has a long tradition of evaluating the results of its censuses. This paper presents evaluation results from the 2010 Census, comparing them to earlier results. The paper discusses net coverage at the national and state level, as well as by age, sex, race, and ethnic group. It discusses components of error, including estimated number missed and counted in error. It also presents data on whole-person and item imputation.     

Comparing the U.S. Decennial Census Coverage Estimates for Children from Demographic Analysis and Coverage Measurement Surveys

Following every U.S. decennial census since 1960, the U.S. Census Bureau has evaluated the completeness of coverage using two different methods. Demographic analysis (DA) compares the census counts to a set of independent population estimates to infer coverage differences by age, sex, and race. The survey-based approach (also called dual system estimation or DSE) provides coverage estimates based on matching data from a post-enumeration survey to census records. This paper reviews the fundamentals of the two methodological approaches and then initially examines the results of these two methods for the 2010 decennial census in terms of consistency and inconsistency for age groups. The authors find that the two methods produce relatively consistent results for all age groups, except for young children. Consequently, the paper focuses on the results for children. Results of the 1990, 2000, and 2010 decennial censuses are shown for the overall population in this age group and by demographic detail (age, race, and Hispanic origin). Among children, the DA and DSE results are most inconsistent for the population aged 0–4 and most consistent for ages 10–17. Results also show that DA and DSE are more consistent for Black than non-Black populations. The authors discuss possible explanations for the differences in the two methods for young children and conclude that the DSE approach may underestimate the net undercount of young children due to correlation bias.     

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.     

Estimates of population size and growth from the 1952-54 and 1961 censuses of the Kingdom of Nepal

Abstract The Census of Nepal conducted in 1961 conforms to the generally accepted requirements for a national census. Some doubt could be raised about the previous census as part of the country was enumerated in 1952 and part in 1954. More serious doubts still could be entertained about earlier censuses, including their very existence, though there are persistent rumours that they were carried out every ten years or so since about the middle of the previous century. We have only been able to lay our hands on some data in respect of four earlier censuses: those of 1911, 1920, 1930 and 1941. Little more is available than population totals for some of the component areas from these four censuses, and even then the boundaries and coverage of the component parts are uncertain.     

Research Note: What Counts as a House? Comparing 2010 Census Counts and Administrative Records

As a tool for fulfilling data needs for small area (subcounty) analysis, demographers are increasingly turning to administrative records such as building permits and tax assessor records as a source of data for use in producing small area demographic estimates. While Census counts are considered to be the “gold standard,” administrative records provide a fine level of spatial detail and a valuable source of information for intercensal years. However, there is uncertainty about the quality of administrative records data for use in estimation. This analysis builds upon earlier research by comparing administrative records-based housing unit estimates developed during the 2000s decade with housing counts from the 2010 Census in San Diego County. Results show that both administrative records and Census counts have strengths and weaknesses that should be understood by the data user.     

An Application of Bayesian Methods to Small Area Poverty Rate Estimates

Efforts to estimate various sociodemographic variables in small geographic areas are proving difficult with the replacement of the Census long-form with the American Community Survey (ACS). Researchers interested in subnational demographic processes have previously relied on Census 2000 long-form data products in order to answer research questions. ACS data products promise to begin providing up-to-date profiles of the nation’s population and economy; however, unit- and item-level nonresponse in the ACS have left researchers with gaps in subnational coverage resulting in unstable and unreliable estimates for basic demographic measures. Borrowing information from neighboring areas and across time with a spatiotemporal smoothing process based on Bayesian statistical methods, it is possible to generate more stable and accurate estimates of rates for geographic areas not represented in the ACS. This research evaluates this spatiotemporal smoothing process in its ability to derive estimates of poverty rates at the county level for the contiguous United States. These estimates are then compared to more traditional estimates produced by the US Census Bureau, and comparisons between the two methods of estimation are carried out to evaluate the practical application of this smoothing method. Our findings suggest that by using available data from the ACS only, we are able to recreate temporal and spatial patterns of poverty in US counties even in years where data are sparse. Results show that the Bayesian methodology strongly agrees with the estimates produced by the SAIPE program, even in years with little data. This methodology can be expanded to other demographic and socioeconomic data with ease.     

1990 censuses to increase use of automation

This article summarizes information from selected reports presented at the 12th Population Census Conference. Ward reports that plans for the 1990 census in many countries of Asia and the Pacific call for increased use of automation, with applications ranging from the use of computer-generated maps of enumeration areas and optical mark readers for data processing to desktop publishing and electronic mail for disseminating the results. Recent advances in automation offer opportunities for improved accuracy and speed of census operations while reducing the need for clerical personnel. Most of the technologies discussed at the 12th Population Census are designed to make the planning, editing, processing, analysis, and publication of census data more reliable and efficient. However, technology alone cannot overcome high rates of illiteracy that preclude having respondents complete the census forms themselves. But it enables even China, India, Indonesia and Pakistan - the countries with huge population and limited financial resources - to make significant improvements in their forthcoming censuses.     

Inferring Directional Migration Propensities from the Migration Propensities of Infants in the United States

Beginning with the 2010 decennial census, the U.S. Census Bureau plans to drop its long-form questionnaire and to replace it with the American Community Survey (ACS). The resulting absence of the larger sample provided by the census count will complicate the measurement and analysis of internal migration flows. In addition, the strategy of averaging accumulated samples over time will mix changing migration patterns. The migration question will refer to a one-year time interval instead of the five-year interval used in the censuses between 1960 and 2000, complicating historical comparisons and the production of multiregional projections based on five-year age groups. Consequently, students of territorial mobility increasingly will find it necessary to complement or augment possibly inadequate data collected on migration with estimates obtained by means of “indirect estimation.” A method is presented that allows one to infer age-specific directional migration propensities at the regional level from birthplace-specific infant population data, which approximates infant migration propensities, and from these infers the migration propensities of all other ages. The method is applied to at the nine-division spatial scale.     

The historical calendar as a method of estimating age: The experience of the Moroccan multi-purpose sample survey of 1961-63

Abstract In censuses and surveys in most African countries it has become the practice to estimate informants' age by the method of the historical calendar. This involves an attempt to relate a remembered historical event, occurring during the subject's childhood, with his age at the time. This paper attempts a first evaluation of the method with particular reference to the 1961-63 multi-round survey in rural Morocco. It is shown that in practice the method is highly complex and easily misunderstood by interviewers and respondents. An attempt to lay down a precise procedure by means of a very detailed questionnaire appeared to yield at best only marginally more accurate results than the simpler procedure used in an earlier round. The more complex questionnaire did, however, introduce new patterns of misuse by the interviewer. There was evidence that the historical calendar gave somewhat better data than eye estimates, but results were highly defective for both methods. It is clear that the method is far from perfect. Interviewer training and supervision remain the key to accurate age determination. If the potential benefits of the complex historical calendar method are to be realized, training and supervision need to be even more thorough than where simpler methods are used.     

An evaluation of the American Community Survey: results from the Oregon test site

The American Community Survey (ACS) is a Census Bureau product designed to provide accurate and timely demographic and economic indicators on an annual basis for both large and small geographic areas within the United States. Operational plans for Census 2010 call for ACS to replace the decennial census long form (Census LF), pending the results of evaluation studies. This plan represents a major change in that variables that traditionally have been collected on a “snapshot” basis once every 10 years would be collected on a “rolling” annual basis. Using a loss function analysis and other tools, this paper reports preliminary findings from a comparison of ACS and Census 2000 results in Multnomah County, Oregon, one of five national “local expert” test sites set up to compare ACS data collected at the time of Census 2000. The preliminary findings suggest that there are notable differences between some of the corresponding variables found in the ACS and Census LF that require more detailed examination. For example, the loss function analysis reveals notable differences for race and disability variables. In other comparisons of corresponding variables between ACS and Census 2000, differences are found within each of the four major areas of interest: (1) demographic characteristics, (2) social characteristics, (3) economic characteristics, and (4) housing characteristics, with housing characteristics showing the least similarity overall. These results also suggest that more detailed examinations are needed to understand differences between corresponding variables collected by ACS and the Census LF.     

Immigration data and national population estimates for the United States

The immigration component in national population estimates is comparatively small, but it is not insignificant and may indeed be an important source of error. Therefore, it warrants the considera-tion of those concerned with population estimates. The paper considers alternative methods for deriving estimates of immigration from the raw data and presents estimates of net immigration from 1950 to 1965. They are developed from estimates previously published by the Bureau of the Census, but they differ at some points where new data have become available or where a review of the data has led to a change in judgment on how best to use them. The paper also presents suggestions on how immigration statistics might be altered for purposes of improving the estimates.Census data may be used to estimate net immigration by three different methods, but upon analysis each method proves to be inadequate. Hence, data based on visas surrendered at the port of entry must be the principal source of immigration estimates. These data have their limitations because (1) they do not cover net arrivals of citizens from abroad and from Puerto Rico, (2) they do not report departures of aliens, and (3) they do not allocate all immigrants to year of entry. Alien registration and passenger data offer possible alternative estimates.The paper attempts to measure unrecorded immigration, discusses how net arrivals of citizens from abroad and from Puerto Rico may be estimated, and how the age, sex, and race of immigrants may be treated.     

Coverage of the population in Census 2000: Results from Demographic Analysis

Since the 1960 Census, Demographic Analysis (DA) has been used by the Census Bureau to evaluate the coverage of the population. Administrative statistics on births, deaths, immigration and Medicare enrollments as well as estimates of legal emigration and net undocumented immigration are used to produce demographic analysis estimates of the population for the census date. These estimates are compared to the Census 2000 data to evaluate coverage in the census. The results are also compared to measures of undercount obtained from dual system estimation. The DA measures substantial reduction in net undercount in Census 2000 compared to 1990. The reductions occur among all demographic categories: all broad age groups, males and females, Blacks and Non-Blacks.     

Book Reviews

In censuses and surveys in most African countries it has become the practice to estimate informants' age by the method of the historical calendar. This involves an attempt to relate a remembered historical event, occurring during the subject's childhood, with his age at the time.

This paper attempts a first evaluation of the method with particular reference to the 1961–63 multi-round survey in rural Morocco. It is shown that in practice the method is highly complex and easily misunderstood by interviewers and respondents. An attempt to lay down a precise procedure by means of a very detailed questionnaire appeared to yield at best only marginally more accurate results than the simpler procedure used in an earlier round. The more complex questionnaire did, however, introduce new patterns of misuse by the interviewer. There was evidence that the historical calendar gave somewhat better data than eye estimates, but results were highly defective for both methods.

It is clear that the method is far from perfect. Interviewer training and supervision remain the key to accurate age determination. If the potential benefits of the complex historical calendar method are to be realized, training and supervision need to be even more thorough than where simpler methods are used.     

Mortality in China 1964-2000

This paper uses data from censuses and surveys to re-estimate mortality levels and trends in China from the 1960s to 2000. We use the General Growth Balance method to evaluate the completeness of death reporting above the youngest ages in three censuses of the People's Republic of China from 1982 to 2000, concluding that reporting quality is quite high, and revisit the completeness of death recording in the 1973-75 Cancer Epidemiology Survey. Estimates of child mortality from a variety of direct and indirect sources are reviewed, and best estimates arrived at. Our estimates show a spectacular improvement in life expectancy in China: from about 60 years in the period 1964-82 to nearly 70 years in the period 1990-2000, with a further improvement to over 71 years by 2000. We discuss why survival rates continue improving in China despite reduced government involvement in and increasing privatization of health services, with little insurance coverage.     

Aboriginal population prospects

Data from the 1991 Census largely confirm earlier projections of the size and structure of the Aboriginal population, although the data for Torres Strait Islanders are markedly inconsistent with previous counts. The 1986 and 1991 Censuses mark the first intercensal period for decades for which Aboriginal population counts have been consistent. This provides an opportunity, taken in this paper, to examine closely the discrepancies between projections and the 1991 Census and to comment on ways in which determinants of Aboriginal population change are diverging from the parameters used for previous projections. We pay particular attention to mortality prospects, because of the occurrence in the 1991 Census of a higher than expected sex ratio and differences between projections and counts for certain age groups. We note the evidence for under-enumeration of the Aboriginal population in particular age groups in the 1991 Census as in previous censuses, and estimate the size of adjustments necessary to correct for some, but not all, of these deficiencies. The analysis shows that Aboriginal fertility increased in the second half of the 1980s.     

Has Income Segregation Really Increased? Bias and Bias Correction in Sample-Based Segregation Estimates

Several recent studies have concluded that residential segregation by income in the United States has increased in the decades since 1970, including a significant increase after 2000. Income segregation measures, however, are biased upward when based on sample data. This is a potential concern because the sampling rate of the American Community Survey (ACS)—from which post-2000 income segregation estimates are constructed—was lower than that of the earlier decennial censuses. Thus, the apparent increase in income segregation post-2000 may simply reflect larger upward bias in the estimates from the ACS, and the estimated trend may therefore be inaccurate. In this study, we first derive formulas describing the approximate sampling bias in two measures of segregation. Next, using Monte Carlo simulations, we show that the bias-corrected estimators eliminate virtually all of the bias in segregation estimates in most cases of practical interest, although the correction fails to eliminate bias in some cases when the population is unevenly distributed among geographic units and the average within-unit samples are very small. We then use the bias-corrected estimators to produce unbiased estimates of the trends in income segregation over the last four decades in large U.S. metropolitan areas. Using these corrected estimates, we replicate the central analyses in four prior studies on income segregation. We find that the primary conclusions from these studies remain unchanged, although the true increase in income segregation among families after 2000 was only half as large as that reported in earlier work. Despite this revision, our replications confirm that income segregation has increased sharply in recent decades among families with children and that income inequality is a strong and consistent predictor of income segregation.     

A Comparative Evaluation of Error and Bias in Census Tract-Level Age/Sex-Specific Population Estimates: Component I (Net-Migration) vs Component III (Hamilton–Perry)

While the housing-unit method continues to be the preferred method nationwide for producing small-area population estimates, this procedures lacks a method for making age/sex-specific estimates. This paper reports evaluation research on implementation of component-based methods for estimating census tract populations with age/sex detail. Two alternatives are explored: (1) the Component I method relying upon estimates of births, deaths, and net-migration and (2) the Component III method relying solely upon 1990 and 2000 Census counts. From an April 1, 2000 base, each method is used to make estimates moving forward to an April 1, 2010 estimate that is compared to the results of the 2010 Census. The two methods are compared in terms of accuracy and bias using both absolute and algebraic mean and median percentage errors. Results are reviewed and discussed in light of their implications for applied demographers tasked with making small-area demographic estimates.     

Estimating the incidence of widow and widower re-marriages in India from census data

Summary In this paper we develop a method for estimating the incidence of widow and widower re-marriages from the current marital status data given in a census or survey. The method basically consists of reversing the procedure of estimating adult mortality from information on widowhood status. The method is applied to the all-India data from the Census of 1971. The principal result is that about one-third of the ever widowed women and slightly fewer than two-thirds of the ever widowed men were currently remarried in 1971. Similar application of the method to earlier censuses, and to state-level data, may provide answers to some of the riddles in Indian sociology.     

Estimating historic population data for small geographies using census housing information

Historical population data for small geographies (e.g. blocks, block-groups, and census tracts) are not available for periods earlier than 1980. In this research note, we propose a geographically-constrained housing unit method (GHUM) to estimate historic population for small geographies using housing age data available in the 1980–2000 censuses. The GHUM is a two-stage method. The first stage follows a traditional housing unit method and provides initial household and group quarter population estimates for small geographies. The second stage takes advantage of the availability of historic data for larger geographies (e.g. counties, states) to adjust the first stage estimates and to provide final estimates. The GHUM is used to estimate 1940–1990 county population and census tract population in Kentucky. The quality of the population estimates is assessed. A two-sample Kolmogorov–Smirnov test indicates that these estimates are statistically reliable at the 10 % significance level.