For trees in tropical forests, competition for light is thought to be a central process that offers opportunities for niche differentiation through light gradient partitioning. In previous studies, a canopy index based on three-dimensional canopy census data has been shown to be a good predictor of species-specific demographic rates across the entire tree community on Barro Colorado Island, Panama, and has allowed quantifying between-species variation in light response. However, almost all other forest census plots lack data on the canopy structure. Hence, this study aims at assessing whether position-based neighborhood competition indices can replace information from canopy census data and produce similar estimates of the interspecific variation of light responses. We used inventory data from the census plot at Barro Colorado Island and calculated neighborhood competition indices with varying relative effects of the size and distance of neighboring trees. Among these indices, we selected the one that was most strongly correlated with the canopy index. We then compared outcomes of hierarchical Bayesian models for species-specific recruitment and growth rates including either the canopy index or the selected neighborhood competition index as predictor. Mean posterior estimates of light response parameters were highly correlated between models (r>0.85) and indicated that most species regenerate and grow better in higher light. Both light estimation approaches consistently found that the interspecific variation of light response was larger for recruitment than for growth rates. However...
Steller sea lion (Eumetopias jubatus) numbers in the Western Distinct Population Segment are beginning to recover following the dramatic decline that began in the 1970s and ended around the turn of the century. Low female reproductive rates (natality) may have contributed to the decline and remain an issue of concern for this population. During the 2000s we found high natality among Steller sea lions in the Gulf of Alaska indicating a healthy population. This study extends these previous estimates over an additional three years and tests for interannual variations and long-term trends. We further examine the proportions of pups to adult females observed on the rookery and nearby haulouts during the birthing season to assess whether census data can be used to estimate natality. Open robust design multistate models were built and tested using Program MARK to estimate survival, resighting, and state transition probabilities in addition to other parameters dependent on whether or not a female gave birth in the previous year. Natality was estimated at 70% with some evidence of interannual variation but a long-term increasing or decreasing trend was not supported by the data. Bootstrap and regression comparisons of census data with natality estimates revealed no correlation between the two methods suggesting that census data are not an appropriate proxy for natality in this species. Longitudinal studies of individual animals are an appropriate method for estimating vital rates in species with variable detection over time such as the Steller sea lion. This work indicates that natality remains high in this region and is consistent with a population in recovery.
Over the past decade a revolution has occurred in the dissemination and analysis of census microdata. This paper discusses the IPUMS-International initiative to liberate census data for researchers world-wide without cost. As of June 2013, academic researchers and policy makers may access, 234 anonymized samples representing 74 countries and totaling over one-half billion person records. The database expands with the addition of 20–30 samples each year. Data are downloadable as extracts from the project website: www.ipums.org/international. To facilitate good use, both metadata and microdata are integrated. The analysis of 450 citations in the project bibliography reveals patterns in publications by country and topic.
High resolution, contemporary data on human population distributions are vital for measuring impacts of population growth, monitoring human-environment interactions and for planning and policy development. Many methods are used to disaggregate census data and predict population densities for finer scale, gridded population data sets. We present a new semi-automated dasymetric modeling approach that incorporates detailed census and ancillary data in a flexible, “Random Forest” estimation technique. We outline the combination of widely available, remotely-sensed and geospatial data that contribute to the modeled dasymetric weights and then use the Random Forest model to generate a gridded prediction of population density at ~100 m spatial resolution. This prediction layer is then used as the weighting surface to perform dasymetric redistribution of the census counts at a country level. As a case study we compare the new algorithm and its products for three countries (Vietnam, Cambodia, and Kenya) with other common gridded population data production methodologies. We discuss the advantages of the new method and increases over the accuracy and flexibility of those previous approaches. Finally, we outline how this algorithm will be extended to provide freely-available gridded population data sets for Africa...
Researchers have recently paid attention to social contact patterns among individuals due to their useful applications in such areas as epidemic evaluation and control, public health decisions, chronic disease research and social network research. Although some studies have estimated social contact patterns from social networks and surveys, few have considered how to infer the hierarchical structure of social contacts directly from census data. In this paper, we focus on inferring an individual’s social contact patterns from detailed census data, and generate various types of social contact patterns such as hierarchical-district-structure-based, cross-district and age-district-based patterns. We evaluate newly generated contact patterns derived from detailed 2011 Hong Kong census data by incorporating them into a model and simulation of the 2009 Hong Kong H1N1 epidemic. We then compare the newly generated social contact patterns with the mixing patterns that are often used in the literature, and draw the following conclusions. First, the generation of social contact patterns based on a hierarchical district structure allows for simulations at different district levels. Second, the newly generated social contact patterns reflect individuals social contacts. Third...
"Poverty maps"-that is, graphic representations of spatially disaggregated estimates of welfare-are being increasingly used to geographically target scarce resources. But the development of detailed poverty maps in many low resource settings is hampered because of data constraints. Data on income or consumption are often unavailable and, where they are, direct survey estimates for small areas are likely to yield unacceptably large standard errors due to limited sample sizes. Census data offer the required level of coverage but do not generally contain the appropriate information. This has led to the development of a range of alternative methods aimed either at combining survey data with unit record data from the census to produce estimates of income or expenditure for small areas or at developing alternative welfare rankings, such as asset indices, using existing census data. This paper develops a set of poverty maps for Azerbaijan that can be used by different users. Two alternative approaches to the measurement and mapping of welfare are adopted. First, a map is derived using imputed household consumption. This involves combining information from the 2002 Household Budget Survey (HBS) with 1999 census data. Second, an alternative map is constructed using an asset index based on data from the 1999 census to produce estimates of welfare at the rayon level. This provides a unique opportunity to compare the welfare rankings obtained at the regional level under the two alternative approaches. In order to visually present the spatially disgaggregated estimates of welfare in Azerbaijan...
The World Bank is developing a project
to develop the capacity of the Central Administration for
Statistics (CAS) of Lebanon to produce demographic and
social statistics. In the absence of population censuses,
the census of buildings and dwelling is one of the few
sources of comprehensive data and information at the
national level. The census that CAS is planning for
2010-2011 has been identified as an initial candidate for
implementation-technical assistance under the current
project. The CAS has requested technical support which will
run over the life of the Census, from the initiation of the
census to the analysis of data, which would extend over the
current and the coming fiscal years. In this context, the
World Bank organized a one month mission to explore the
prospects for this technical assistance. The first two weeks
of the mission, Monday 23, March 2009 to Saturday 4, April
2009 focused on assessment. The second two weeks, Monday 6,
April 2009 to Saturday 18, April 2009, focused on technical
assistance. This note is divided into four volumes. Volume I
is an assessment made during the first half of the mission.
Volume II addresses the questions related to the Design and
Management of the Census of Buildings and Dwellings...
The authors combine household survey and
census data to construct a provincial poverty map of Vietnam
and evaluate the accuracy of geographically targeted
antipoverty programs. First, they estimate per capita
expenditure as a function of selected household and
geographic characteristics using the 1998 Vietnam Living
Standards Survey. Next, they combine the results with data
on the same household characteristics from the 1999 census
to estimate the incidence of poverty in each province. The
results show that rural poverty is concentrated in 10
provinces in the Northern Uplands, 2 provinces in the
Central Highlands, and 2 provinces in the Central Coast. The
authors use Receiver Operating Characteristics curves to
evaluate the effectiveness of geographic targeting. The
results show that the existing poor communes system excludes
large numbers of poor people, but there is potential for
sharpening poverty targeting using a small number of
easy-to-follow measure household characteristics.
This paper analyses 2001 Census data relating to Indigenous people living in the Alice Springs town camps as compared to three other population groups: Indigenous people in the rest of Alice Springs, non-Indigenous people in Alice Springs and Indigenous people living in the outlying communities of the region around Alice Springs. The paper builds on earlier work which observed and reported on the collection of the 2001 Census in the Alice Springs town camps. The paper finds expected similarities between Indigenous town camp residents and Indigenous people in outlying communities. It also finds expected socio-economic differences between town camp residents and Indigenous people living in the rest of Alice Springs, and even greater differences in comparison with the non-Indigenous residents of Alice Springs. The paper identifies a number of shortcomings and inadequacies in the 2001 Census data used, but argues that these do not nullify the usefulness of the larger exercise. Rather they point the way to improvements in census collection procedures which may hopefully be implemented in 2006.; no
The paper presents an analysis of indigenous household demography and economic status relative to non-indigenous Australian households. An innovative combination of economic analysis of 1996 Census data and ethnographic research is used, and reveals that indigenous households are experiencing substantial and multiple forms of economic burden in comparison to non-indigenous Australian households and that they display significantly different characteristics. The findings highlight a number of policy implications.; yes
In August 2001 three CAEPR researchers, each based in a different community, observed the conduct of the national Census in the Northern Territory and Cape York Peninsula. The purposes of this research were twofold: to evaluate the ABS’s Indigenous Enumeration Strategy as it was applied in this particular context, and to assess the quality of the data that were collected. This paper, based on research in a remote Northern Territory outstation community, focuses on the questions that were designed to elicit information about household structure. The data collected in the census are a vital tool for the formulation of policy across a very broad range of issues. Pursuing the red herring of forcing Indigenous families and households into mainstream categories is a waste of time and effort, and diverts attention from the significant underlying issues. If the quantifiable population characteristics of Indigenous Australians are to emerge clearly from census data, the questions on the Indigenous form need to be as culturally neutral as possible, in order to minimise misunderstanding on the part of the Indigenous interviewers and respondents. The designers of the census need to step back from the questions on household structure, and decide precisely what information they wish to elicit. Is it information primarily about family structure...
Historical census data provide a snapshot of the era when our ancestors lived. Such
data contain valuable information for the reconstruction of households and the tracking
of family changes across time, which can be used for a variety of social science
research projects. As valuable as they are, these data provide only snapshots of the
main characteristics of the stock of a population. To capture household changes
requires that we link person by person and household by household from one census
to the next over a series of censuses. Once linked together, the census data are
greatly enhanced in value. Development of an automatic or semi-automatic linking
procedure will significantly relieve social scientists from the tedious task of manually
linking individuals, families, and households, and can lead to an improvement
of their productivity.
In this thesis, a systematic solution is proposed for linking historical census data that integrates data cleaning and standardisation, as well as record and household linkage over consecutive censuses. This solution consists of several data pre-processing, machine learning, and data mining methods that address different aspects of the historical census data linkage problem. A common property of these methods is thatthey all adopt a strategy to consider a household as an entity...
The Australian Census of Population and Housing is a census of people not places. However, where people live and work can be of major relevance in our search for explaining and understanding their behaviour. This paper argues that the place dimension in the Australian census has not been exploited very effectively in this respect. Three dimensions of the issue are addressed. Firstly, the spatial units commonly used for analysis of census data often are not appropriate to the problem being investigated. The spatial units in the Australian Standard Geographical Classification (ASGC) used for census data rarely represent meaningful social, economic and environmental regions. Secondly, the use of a simple urban/rural dichotomy is criticised as being a very blunt instrument to differentiate settlement types. Thirdly, the relationship between people and place in the census is discussed. While for the most part the census relates people to a single location—their place of usual residence—this is only one of the places with which people regularly interact. It is suggested that there is a need to adopt practices in the census which allow a range of population geographies to be defined. In conclusion it is argued that innovation in the Australian census...
This study exploits a natural experiment
to investigate the impact of land reform on the fertility
outcomes of households in rural Ethiopia. Public policies
and customs created a situation where Ethiopian households
could influence their usufruct rights to land via a
demographic expansion of the family. The study evaluates the
impact of the abolishment of these pronatal property rights
on fertility outcomes. By matching aggregated census data
before and after the reform with administrative data on the
reform, a difference-in-differences approach between reform
and non-reform districts is used to assess the impact of the
reform on fertility outcomes. The impact appears to be
large. The study estimates that women in rural areas reduced
their life-time fertility by 1.2 children due to the reform.
Robustness checks show that the impact estimates are not
biased by spillovers or policy endogeneity.
The objective of the socio-economic
atlas (SEA) for Vanuatu is to present key indicators of the
socioeconomic status of Vanuatu population, at the areas
council level. It allows for comparisons of various
development indicators across various geographical areas.
The atlas has been developed through a consultative process
with various Government agencies and development
organizations. The atlas provides representative
socio-economic indicators at the level of area council
(district), which is the smallest administrative division
unit in Vanuatu. Most of the indicators presented in the
atlas have been derived from the Vanuatu 2009 census data,
which is rich in terms of the development indicators
captured. The content of the census questionnaire defines
the boundaries of what indicators can be presented. The
authors have used small area estimation techniques to derive
estimates of consumption-based poverty and inequality, by
combining the use of the 2009 census data with the 2010
household income and expenditure survey (HIES) data. A
separate technical paper describes the methodology used in
doing this and is available from the Vanuatu national
statistical office (VNSO) and the World Bank. The atlas
includes five key groups of socio-economic indicators for
population. Section A covers the indicators of household
wellbeing in terms of consumption-based poverty rates and
inequality indices. Section B looks at the sources of
livelihoods for households in terms of livestock numbers and
share of households engaged in various economic activities.
Section C focuses on the households' living conditions
by looking at the quality of dwelling...
Dois problemas relacionados com a utilização de dados agregados são bastante conhecidos e citados na literatura. O primeiro deles diz respeito à não coincidência entre as unidades para as quais os dados são disponibilizados e aquelas para as quais os dados são necessários; o segundo está relacionado com a estabilidade temporal das unidades de agregação. Como solução para esses problemas este trabalho propõe a utilização de células regulares dispostas em um sistema de grade para a agregação e disseminação de dados censitários, denominada "grade estatística". As células desta grade têm pequenas dimensões, podendo ser consideradas como "tijolos" que se juntam para formar qualquer recorte espacial desejado e não se alteram ao longo do tempo. A utilização de dados agregados em unidades de pequenas dimensões proporciona também um aumento do potencial analítico. Foram selecionadas duas unidades da federação ¿ Pará e São Paulo - para a criação da metodologia de geração da grade estatística e para a execução de aplicações práticas. A abordagem selecionada é híbrida, mesclando agregação e desagregação. A primeira utiliza os microdados censitários associados aos seus atributos de localização para a agregação dos dados; a segunda utiliza métodos espaciais e/ou estatísticos juntamente com dados secundários para a realocação espacial dos dados. Os resultados obtidos demonstraram que a abordagem híbrida é viável e deve ser utilizada quando existe uma grande variação na qualidade dos dados e a área de estudo abrange grandes extensões. Os dados obtidos apresentaram uma boa qualidade e a sua utilização permitiu a execução de análises com um maior nível de desagregação espacial...
OBJECTIVES--To assign census data to general practice populations and to test accuracy of different procedures for estimating the proportion of patients aged over 64. DESIGN--Patients' postcodes from patient register of one family health services authority and the directory linking postcodes to census enumeration districts were used to locate patients in their census area of residence. With different levels of census geography and four different allocation procedures, proportion of patients aged over 64 in each area was used to predict proportion of patients aged over 64 in each general practice. Predicted figures were compared with real figures from each practice register to assess accuracy of allocation methods. SETTING--Data from 1991 census and from 73 practices administered by one family health services authority. MAIN OUTCOME MEASURES--Actual and predicted proportions of patients aged over 64 in general practice populations. RESULTS--Correlations between actual and predicted proportions of patients aged over 64 were significant for all four allocation procedures--values of 0.66, 0.7, 0.84, and 0.84 were achieved (P < 0.0005). Predicted ranges of proportions of patients aged over 64, however, were well short of those that actually existed...
This article presents data derived by the USGS Pliocene Research, Interpretation and Synoptic Mapping (PRISM) Project. PRISM has generated planktic foraminifer census data from core sites and outcrops around the globe since 1988. These data form the basis of a number of paleoceanographic reconstructions focused on the mid-Piacenzian Warm Period (3.264 to 3.025 million years ago). Data are presented as counts of individuals within 64 taxonomic categories for each locality. We describe sample acquisition and processing, age dating, taxonomy and archival storage of material. These data provide a unique, stratigraphically focused opportunity to assess the effects of global warming on marine plankton.
Methodologies now commonly used for the construction of poverty maps assume a substantial degree of homogeneity within geographical areas in the relationship between income and its predictors. However, local labor and rental markets and other local environmental differences are likely to generate heterogeneity in such relationships, at least to some extent. The purpose of this paper is to argue that useful if only indirect and suggestive evidence on the extent of area heterogeneity is readily available in virtually any census. Such indirect evidence is provided by non-monetary indicators–such as literacy, asset ownership or access to sanitation–which are routinely included in censuses. These indicators can be used to perform validation exercises to gauge the extent of heterogeneity in their distribution conditional on predictors analogous to those commonly used in poverty mapping. We argue that the same factors which are likely to generate area heterogeneity in poverty mapping are also likely to generate heterogeneity in such kind of validation exercises. We construct a very simple model to illustrate this point formally. Finally, we evaluate empirically the argument using data from Mexico. In our empirical illustrations, the performance of imputation methodologies to construct maps of indicators typically feasible with census data alone is indeed informative about how effectively such methodologies can produce correct inference in poverty mapping.
The conventional study of demographic issues typically focuses on the components of population, and of population change over time. The data required for measuring major demographic events include measures of births, union formation and dissolution, deaths and migration. Population enumeration has a long history in Australia. Vital (or civil) registration and routine censuses were collected following European settlement, providing important information on demographic events in the Australian colonies. To the extent that demography measures the dynamics of population, these data collections remain important sources of population data that are essential to demographic enquiry. However, demographic study is substantially broader than the mathematical measurement of these components. Research on population issues is concerned with the social, economic, cultural, environmental, epidemiological and many other determinants of demographic events. This has resulted in the study of population being strongly influenced by, and conducted from, many disciplinary perspectives. This review focuses on some of the major data sources used for demographic enquiry. Aside from the essential sources of vital registration and census data, access to administrative and survey data is important for analytical purposes.