Modal Choice in the Pittsburgh Metropolitan Statistical Area: An Exploratory Data Analysis

Journey-to-work mode choice is intertwined with ideological and pragmatic issues. This article reexamines such issues using socioeconomic data from the decennial census and American Community Survey (ACS). It investigates the structure of variables with exploratory data analysis (EDA) because this technique advises the formation of hypotheses and the specification of cause and effect. Traditional EDA reveals the nonnormal structure of raw data, mapping illustrates associations between transit and income, and both methods suggest the presence of a transit-by-choice population among affluent metropolitan residents. The results yield three hypotheses concerning propensity to use transit that have previously received little attention.     

Measuring Demographic Change: The Split Tract Problem

Census tracts in rapidly growing areas often are split into two or more tracts between decennial censuses. The mismatch of tract boundaries between decades poses difficult problems for those researchers interested in measuring demographic change in small areas. The most common solution is to make tracts in both years conform to the earlier boundaries-data from the split tracts are aggregated. An alternative is to apportion data for the earlier year on the basis of land area. A third method estimates the distribution of data for the earlier year by the proportion of population later living in the various split tracts. Comparison of these three methods suggests that, in typical situations, the latter method results in less overall error.     

1982年以来中国省级区域城市化水平趋势

城镇人口数据不一致的问题非常严重, 几乎没有系统的省级区域城市化数据。这种情况部分是因为人口普查城镇人口定义的变化,部分是由城镇设置标准的变动引起的。人口普查是全国和各省区城镇人口数据的重要来源。但是由于人口普查的城镇人口定义在不断变化,城镇人口数据很多是前后不一致的,必须进行相应调整。本文首先讨论改革时期新的城市化进程,澄清城镇人口定义的变化,然后概括地说明估计全国和区域城镇人口所用的一个基于双轨城市化概念模式的区域方法。将调整后的1982年和2000年人口普查得到的城镇人口作为计算的基础数据,对1982~2000年中国各省的城市化水平进行估计。在估计结果的基础上,分析1982~2000年中国城市化过程的主要空间特征。揭示了1982~2000中国省级区域城市化发展的主要趋势。本文最后为将来城镇人口的统计提出一些建议。     

Can Census Offices publish statistics for more than one small area geography? An analysis of the differencing problem in statistical disclosure

The paper describes a problem faced by National Statistical Offices when publishing the results of decennial censuses for small geographical areas. If they publish statistical tables for two or more sets of areas, users can compare the tables and produce new statistics for the areas formed by differencing, which may have populations below confidentiality thresholds. To investigate the problem, the authors construct a software system and carry out a series of experiments using a large synthetic population base for Yorkshire and Humberside. The results indicate that publishing statistics for zones close in size to the primary areas is not safe unless the zones have been carefully designed. However, publishing statistics for sufficiently large areas such as 5 km grid squares or postal sectors alongside enumeration districts is safe.     

中国流动人口概念和数据的有效性与国际可比性

长期以来,“流动人口”和“人口流动”这两个概念、以及基于这两个概念获取的数据在中国相关研究和政策制定中得到广泛使用,甚至主导着中国人口迁移流动的研究。在国际背景下对这两个概念和相关数据的有效性和可靠性进行了深入地检视,并通过对若干人口普查数据和流动人口动态监测调查数据的分析,揭示“流动人口”和“人口流动”在测量人口迁移流动事件时的失效和失真。结果表明,“流动人口”和“人口流动”概念及相关数据已与现实的迁移流动事件和过程严重脱节;它们既可能因高估迁移流动人口的规模而失真,也可能因系统性遗漏某些迁移流动人口（如城—城流动人口）而失效,同时还严重干扰对现实人口迁移流动方向的判断。此外,基于“人户分离”得到的流动人口数据还存在着不能用于“率”指标的计算和缺乏国际可比性等问题。基于此,本文认为中国人口迁移流动的相关概念、测量和数据收集应回归其反映空间变动事件的本质功能,逐步扩大使用基于5年前常住地（乃至1年前常住地）变动的人口迁移流动数据,并充分利用人口登记和行政管理数据开发基于迁移事件的人口迁移流动数据,为分析和判断中国人口迁移流动的演变趋势和规律提供有效且可靠的数据基础。     

Spatial redistribution of the Torres Strait Islander population: a preliminary analysis

Until World War II, Torres Strait Islanders were restricted in their distribution to the Torres Strait itself. Since that time, migration to the Australian mainland has contributed to a significant redistribution with the majority of Torres Strait Islanders now resident in the major cities of eastern Australia. Despite the importance of migration in determining Torres Strait Islander involvement in the labour market, study of their population movement has been limited and such analysis as does exist is unsystematic, spatially restricted and generally dated. This paper is therefore an attempt to draw from the literature what is known about the redistribution of Torres Strait Islanders and to supplement this with an analysis of the most recently available internal migration data from the 1986 and 1991 censuses. While it appears that the search for employment was an important stimulant for migration in the past, this is probably less so now, not least because Torres Strait Islanders now find themselves located in places where labour markets exist. No evidence is found from the 1986 Census to support the idea of sustained redistribution away from areas of long standing settlement in northern Queensland. This contrasts intuitively with distribution patterns revealed by the 1991 Census, and the extent to which this discrepancy is due to migration or census error raises a critical issue in the analysis of Islander population change.     

Residential Mobility of the Poor and the Growth of Poverty in Inner-Ring Suburbs

This study builds on recent research on the growth of suburban poverty by tracking bi-annual poverty trends in inner suburbs from 1989 to 2005 through data reported by the Panel Study of Income Dynamics. Contrary to analyses based on the 1990 and 2000 censuses, this research finds that inner-ring suburban poverty increased from 1989 through 1997 but then declined and stabilized at levels similar to those of 1989. It will be shown that most of these changes were driven by transitions into and out of poverty, and that the migration of the poor between central-city and suburban neighborhoods has little effect on poverty rates. These results suggest that such poverty is highly dependent upon economic conditions, which may indicate an increase in inner-ring poverty since 2005.     

Interprovincial Migration,Population Redistribution,and Regional Development in China: 1990 and 2000 Census Comparisons*

Until recently, migration has had a limited role to play in China's space economy because of central‐planning logic and mechanisms. Mobility increases and economic restructuring since the 1980s, however, call for new conceptualizations of migration. Using interprovincial migration data from China's 1990 and 2000 censuses, I analyze migration rates, migration effectiveness, population growth, net migration flows, and spatial focusing of migration. The analysis supports the notions that migration is an increasingly effective factor of population redistribution and that it has a strong relationship with regional development. While these relationships have been documented in many other parts of the world, they have been less well addressed in the case of China. Regional divergence in economic development during the 1990s was accompanied by a marked increase in interprovincial migration and sharply concentrated migration flows, especially from relatively poor central and western provinces to the rapidly growing eastern region. These results suggest that migration theories that draw from experiences of capitalist economies may be of increased relevance to China.     

The spatial mobility of two generations of young adults in Norway

"This article presents results from a longitudinal study using data from the Norwegian population register, combined with data from the 1970 and 1980 censuses. For two generations, those born in 1948 and 1958, successive migrations are considered and the effects of various sociodemographic characteristics on migratory behaviour are explored....Event-history analysis is used to examine the duration of stay at the place reached at age 22, and the effects of individual characteristics on this duration. Since a distinction is made between intra- and inter-regional migration, it has been possible to show that these effects vary significantly depending on whether we are dealing with short- or long-distance migration."     

Recent urban growth in Papua New Guinea

Using population estimates from recent censuses and from the 1977-1978 Urban Population Survey, the author examines trends in urban growth in Papua New Guinea. Reasons for the differences between actual and predicted rates of urban growth are investigated     

Simulating trends in poverty and income inequality on the basis of 1991 and 2001 census data: a tale of two cities

How much does the 2001 census tell us about the changes in people's life in British cities and regions since 1991? This paper attempts to answer this question by telling the stories of two British northern cities: Leeds and Sheffield. In particular, the paper investigates and compares socio-economic change in these cities on the basis of actual 1991 and 2001 census data as well as estimated non-census data. A static spatial microsimulation model is used to combine the outputs of the 1991 and 2001 censuses of UK population with data from the British Household Panel Survey (BHPS) data. In particular, selected Small Area Statistics (SAS) tables from the 1991 and 2001 censuses are used as constraints in the spatial microsimulation modelling exercise, which aims to reweight BHPS household records so that they satisfy these constraints. The paper briefly discusses the change in these census variables across different localities of the two cities. It is then shown how the changes in these variables affect the simulation of non-census variables. Further, the microsimulation model is used to estimate the trends in income inequalities and child poverty between and within the two cities. Finally, the paper discusses the implication of the research findings for policy formulation.     

Measuring the Spatial Focus of Migration Patterns

The changing territorial concentration of migration flows is of interest to many geographers, yet we still do not have a widely accepted index of spatial focus. The much used index of migration efficiency has been shown to be an inadequate index of such spatial concentration, and two candidates have been suggested to replace it: the Gini index and the coefficient of variation. Both are examined in this paper, and a comparative assessment is offered. Data from the 1970, 1980, and 1990 censuses are used to illustrate the two measures. An examination of the findings reveals that the coefficient of variation measure indicates higher levels of spatial focus than does the Gini index for states with highly concentrated flows.     

Guest editorial: the 2001 UK census: remarkable resource or bygone legacy of the 'pencil and paper era'?

National censuses are expensive. They are conducted infrequently. They collect information that some feel infringes their human rights, and people are required by law to complete them. The outputs are not perfect, and in some situations may be misleading. Some suggest that censuses hark back to a period when regularly collected administrative data were not available. These are some of the views held about national censuses. Why, then, would others argue that they are an essential resource? In this paper, we consider some of the pros and cons of conducting national censuses, before introducing a series of papers that draw on early data available from the 2001 UK census. We argue that these papers, and the wealth of research that will be conducted in the future with 2001 census data, make a strong case for supporting the compulsory collection of personal information about the 'entire' population every ten years.     

全面二孩背景下中国省际人口迁移格局预测及城镇化效应

采用第六次中国人口普查数据,基于全面二孩实施背景,预测未来中国与省际城乡人口规模以及省际人口迁移规模;采用2010年人口数据和2020年预测人口数据,从对比视角分析了中国省际人口迁移格局变化及其对城镇化发展的影响。研究发现：① 城乡全面放开二孩政策不会带来区域人口数量的剧烈反弹;② 综合考虑省际人口迁移方向与强度,将中国31个省份划分为4种类型;③ 省际人口迁移促进了城镇化率的提高及省际差异的缩小,对2010~2020年中国城镇化率的增加的贡献占到了30.77%。     

Spain. Regional differences in population density in 1986: the end of a process of increasing internal disequilibrium?

This is an analysis of regional differences in population trends in Spain during the twentieth century. Data are from a variety of official sources, including the censuses of 1900, 1960, 1970, and 1981. The author notes that up until 1975, interregional migration flows had acccentuated regional economic differences. However, the economic problems that have occurred since 1975, coupled with the political changes associated with greater regional autonomy, have resulted in new trends in internal migration that could have significant effects on the future distribution of the country's population.     

空气质量对中国人口迁移的影响

随着中国流动人口群体构成和迁移模式的持续变化,空气质量等舒适性要素逐渐成为塑造人口迁移空间格局的重要因素。基于2000年以来的人口普查和抽样调查数据,本文探讨了空气质量对人口迁移影响的总体特征、变动趋势和作用模式。研究发现,空气质量已逐渐成为影响中国人口迁移格局的重要因素,且主要表现为推力作用。空气质量直接关系到人口迁出决策,污染严重的地区更难留住人;而在迁入地选择过程中,收入水平和就业机会则更为重要,但其影响近年来有所弱化,城市吸引力更加综合多元。此外,研究还验证了教育资源对人口迁移的导向性作用,并从人口迁移的角度发现了城市群作为城镇化主体形态的地位在持续强化。     

2000—2020年中国人口分布格局演变及影响因素

基于第五、六、七次全国人口普查数据,本文分析了2000—2020年中国人口分布的空间格局、集散态势和影响因素。结果表明,中国人口分布依然保持东密西疏的基本格局,胡焕庸线两侧的自然地理环境差异性决定了这一格局的长期稳定性;人口空间集中化趋势在21世纪初的10年内主要发生在东南半壁,但在2010—2020年间成为各区域的共同特征。省会城市的人口集聚能力持续增强,2010—2020年的优势更加凸显,但这种行政力量主导的首位度提升效应将随着全省发展阶段的演进而逐渐弱化。人口变动的区域分化明显：沿海城市群的空间连绵化逐渐形成了强吸引力、高承载力的沿海人口增长带,东北地区几乎转向全面的人口收缩,中部各省依托省会展开的人口竞争依然激烈,川渝黔地区普遍实现了人口的止降回增,西北地区则面临人口收缩风险。此外,区域人口增长的驱动因素逐渐从经济要素主导转为经济要素和舒适性要素并重,各地区舒适性的差异可能将成为影响未来人口空间格局变化的重要因素。     

Patterns and causes of uncertainty in the American Community Survey

In 2010 the American Community Survey (ACS) replaced the long form of the United States decennial census. The ACS is now the principal source of high-resolution geographic information about the U.S. population. The margins of error on ACS census tract-level data are on average 75 percent larger than those of the corresponding 2000 long-form estimate. The practical implications of this increase is that data are sometimes so imprecise that they are difficult to use. This paper explains why the ACS tract and block group estimates have large margins of error. Statistical concepts are explained in plain English. ACS margins of error are attributed to specific methodological decisions made by the Census Bureau. These decisions are best seen as compromises that attempt to balance financial constraints against concerns about data quality, timeliness, and geographic precision. In addition, demographic and geographic patterns in ACS data quality are identified. These patterns are associated with demographic composition of census tracts. Understanding the fundamental causes of uncertainty in the survey suggests a number of geographic strategies for improving the usability and quality ACS.     

A geographic analysis of non-Russian minorities in Russia and its ethnic homelands

"The paper...analyzes the characteristics of 27 million non-Russians who constituted 18 percent of the population of the Russian Federation and its 31 ethnic homelands in 1989. Utilizing data from all Soviet censuses (from 1926), it reviews long-term historical trends; growth patterns related to urban-rural differences, family size, regional contrasts in rates of natural increase, and specific ethnic traits; migration patterns; factors influencing language shifts to the Russian; effect of location inside or outside homeland; and the influences of transportation, cities, and economic development in individual homelands."     

Declining towns in the former USSR

"The paper comprises an update of an earlier study...focused on towns with declining population during the 1959-1970 period. Based on recently published data on individual urban centers with 15,000 or more inhabitants reported in the 1979 and 1989 censuses, it identifies centers where population declined from 1970 to 1989. The study also assesses selected geographical aspects, economic functions, and size characteristics of such urban centers. Comparisons with data from the 1959-1970 period are made to arrive at a 30-year perspective."