The consequences of metropolitan decentralization for personal gasoline consumption

It is often argued that more decentralized and spatially dispersed metropolitan areas require their residents to consume more gasoline than more centralized metropolitan areas. This notion is deduced from the assumption that, (1) populations decentralize, and (2) as this happens, people locate at distances farther removed from metropolitan centers which house most of the services, shops and jobs which suburban residents must travel to. In this article, it is argued that, at advanced stages of metropolitanization, the places to which people travel also decentralize and as this happens the gasoline consumption of metropolitan residents in more decentralized areas actually becomes lower than that of residents in more centralized areas. The latter argument is tested using multiple indicators of decentralization, and a number of control variables. All of the indicators of expansion relate to gasoline consumption in the predicted direction; the implications of this for energy and location policy are discussed.This research was supported in part by grants from the National Science Foundation (SOC 7826121 and SOC 77-07579), and the Program of University Research, U.S. Department of Transportation (80-193).     

Selection for divergent emigration rates in laboratory populations ofMusca domestica

Summary High and low emigration rates through a laboratory system were selected for in populations of house flies (Musca domestica L.). Emigration consisted of movement of flies from on plastic box to another by way of a connecting tube. Selection was carried out by first dividing a wild population of flies into two lines and then selecting for movement from the box in one line and against movement from the box in the other line. The selection experiment was performed twice. In both experiments a statistically significant difference between the two strains was obtained in three to four generations of selection. In the second experiment, after 5 genrations the mean number of high emigration rate flies emigrating in 1 hour was 4.37 times the mean number of low emigration rate flies and in 24 hours was 2.81 times the number of low emigration rate flies. The second experiment was terminated after 6 generations, but the first experiment was continued for 35 generations. In this case, divergence ceased in roughly 15 generations. The possible relevance of the findings to laboratory population experiments in which spatial discontinuities are included is discussed. This study was supported by a research grant of the National Science Foundation (Environmental Biology GB 4567) to Prof. DavidPimentel. The author wishes to thank Prof.Pimentel for his aid and encouragement.     

A Critical Examination of the Environmental Mastery Scale

The Psychological well being Inventory (PWBI) is a multidimensional instrument that has enjoyed widespread use in a variety of research initiatives, from small-scale studies to national surveys. Recent empirical investigation of the measure has raised questions about its validity. This study examines the factorial validity of the Environmental Mastery Scale of the PWBI, a construct that receives much attention in mental health research. The results of a confirmatory factor analysis did not support the unidimensional factor structure of the measure. Correlated uniqueness models were also examined, which did not reveal evidence of a method effect. There are problems with the measure at the item level, which also raises significant questions about the underlying theory of its parent measure. This research uses data from the Wisconsin Longitudinal Study (WLS) of the University of Wisconsin-Madison. Since 1991, the WLS has been supported principally by the National Institute on Aging (AG-9775 and AG-21079), with additional support from the Vilas Estate Trust, the National Science Foundation, the Spencer Foundation, and the Graduate School of the University of Wisconsin-Madison. A public use file of data from the Wisconsin Longitudinal Study is available from the Wisconsin Longitudinal Study, University of Wisconsin-Madison, 1180 Observatory Drive, Madison, Wisconsin 53706 and at http://www.ssc.wisc.edu/wls/data/. The opinions expressed herein are those of the authors.     

Immigration,assimilation and growth

This paper analyzes the welfare effects of immigration and its subsequent effect on ethnic diversity in a model featuring human capital spillovers which depend on the degree of ethnic heterogeneity, variation rates of time preference across individuals and endogenous levels of immigration and assimilation. In the model, an increase in ethnic diversity reduces the spillovers effect for the majority. Nonetheless, immigration can be welfare improving for the majority ethnic group even if it increases the degree of diversity as long as it raises the average human capital level and/or growth rate by increasing the proportion of people with low rates of time preference. However, if an economy is too homogenous, it will not be able to attract immigrants. Finally, if the level of immigration is not too high, then immigration also raises the net benefits to assimilation which leads to a more homogenous economy. Received: 18 February 1997 / Accepted: 16 July 1997     

Projections of the ethnic minority populations of the United Kingdom 2006-2056

The ethnic minority populations in the UK are growing substantially through immigration, a youthful age structure, and in some cases relatively high fertility. Their diverse demographic and socioeconomic characteristics have attracted considerable academic and policy attention, especially insofar as those distinctive characteristics have persisted in the generations born in the UK. No official projections of the UK ethnic populations have been published since 1979. This article provides projections to 2056 and beyond of 12 ethnic groups. Given overall net immigration and vital rates as assumed in the office for National Statistics 2008-based Principal Projection, and the ethnic characteristics estimated here, the ethnic minority populations (including the Other White) would increase from 13 percent of the UK population in 2006 to 28 percent by 2031 and 44 percent by 2056, and to about half the 0-4 age group in 2056. Alternative projections assume various lower levels of immigration. Possible implications of projected changes are discussed.     

The MOS Alienation Scale: An alternative to Srole's Anomia Scale

A growing number of sociologists believe that Srole's Anomia Scale, whether modified or not, is too inclusive to measure anomie in any meaningful way when using survey research techniques among subcultures. Evidence from the National Opinion Research Center's annual General Social Survey, which is a cross-sectional sample of adults in the United States, tends to give credence to this criticism — that is, although Srole's Anomia Scale displays a modest degree of internal reliability, it nevertheless lacks external validity in surveys on national subpopulations. This study illustrates the relative superiority of the Margins of Society (MOS) Alienation Scale, which comprises operations from theories on anomie and social isolation. A subculture of homeless Alaska Natives were personally interviewed to document the attributes of this new alienation scale and the results from this exploratory study suggest that further analysis should prove useful for studying alienation within other ethnic groups.     

Ethical Issues in Disaster Research: Lessons from Hurricane Katrina

Conducting research in the wake of a catastrophic event imposes the dual responsibilities on researchers of protecting the rights of the survivors as research subjects, while also ensuring research quality and the dissemination and application of findings. This article, based partially on the authors’ experiences of conducting research in school districts following Hurricane Katrina, examines the ethical issues that arise when working with survivors, reticent organizations, and institutional review boards. Challenges experienced by researchers concerning access, informed consent, confidentiality, subject compensation, and enlisting the assistance of stressed institutions are described. This material is based upon work supported by the National Science Foundation under Grant No. 0036566000. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.     

Fertility and the economy

I relate the demand for children to parental incomes and the cost of rearing children — especially to the value of the time spent on child care and to public policies that change the cost of children. This paper also links the demand for children to investments in their human capital and other dimensions of the so-called quality of children. Fertility is shown to depend too on child and adult mortality, uncertainty about the sex of children — if there is a preference for boys, girls, or for variety — uncertainty about how long it takes to produce a conception, and other variables.Since biological necessity dictates that succeeding generations overlap, it is not surprising that fertility in one generation influences the fertility of succeeding generations. The overlapping generations approach provides a useful framework for relating fertility choices to population growth and macroeconomic changes.The modern approach to fertility leads to very different interactions between population growth and economic growth than is implied either by Malthusian or the usual neo-classical growth models. In particular, it provides a framework for analyzing how societies escape a Malthusian-like stagnating equilibrium and embark on the journey toward becoming modern economies, where per capita incomes, human capital, and physical capital all continue to grow, fertility declines to rather low levels, and married women participate extensively in the labor force.This essay was prepared for the Nobel Jubilee Symposium, Lund, Sweden, December 5–7, 1991. I have had valuable comments from James Heckman, Robert Willis and my discussants at the symposium: Allesandro Cigno and Richard Easterlin, and useful assistance from Becky Kilburn. I am indebted to the National Institute for Child Health and Human Development award R37-HD22054 and National Science Foundation award SES-90-10748.     

Intermarriage patterns and social cohesion among first, second and later generation Australians

Studies of ethnic intermarriage in Australia have found that group size, residential segregation, and religious homogeneity, as well as social distance from the dominant (Anglo) cultural group, are important factors determining the likelihood of ethnic intermarriage. However, studies to date have predominantly focused on the first generation, and have less to say about interethnic marriages among members of the second and later generations. This paper analyses marriage patterns across immigrant generations, focusing on specific European ancestries: German, Dutch, Greek, Italian, Polish and Hungarian, contrasted with members of the dominant group. The results reveal strong effects of ancestry, immigrant generation, cross-generational preferences, and intergroup exchanges, as well as a few disjunctions reflecting discontinuities in the history of settlement among different immigrant groups. The results also show that social distance is important in determining the likelihood of intermarriage, as well as the cohesiveness of ethnic groups across generations.     

The influence of first generation fertility and economic status on second generation fertility

This paper examines the impact of parental economic status and family size on the actual and expected fertility of adult children using longitudinal data from two generations of families participating in the Panel Study of Income Dynamics. There was a modest positive relationship between first generation family size and second generation fertility. More importantly, the ideal family size of the parental family was more closely related to fertility behavior and plans in the second generation than was actual parental family size. In addition, the data revealed the hypothesized negative correlation between parental financial status and second generation fertility behavior and plans. Several mechanisms which could produce the correlation between parental characteristics and the fertility of their children are explored.The analysis reported in this paper was supported by Contract NO1-HD-42856 from the National Institute for Child Health and Human Development, Center for Population Research. Dr. Thornton is affiliated with the Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI 48106. Requests for reprints should be directed to him.     

The effect of maternal employment on teenage childbearing

This paper estimates the effect of a mothers employment on her teenage daughters likelihood of birth. Using data from the United States, the National Education Longitudinal Survey of 1988, the author finds that teenagers with working mothers who attend relatively wealthy schools are more likely (77%) to have a birth compared to teens who attend similar schools but have non-working mothers. In contrast, teenagers with working mothers who attend relatively poor schools are less likely (18%) to have a birth compared to teens who attend similar schools but have non-working mothers.I am indebted to Marcia Carlson, Thomas DeLeire, Angela Fertig, Brian Jacob, Darren Lubotsky, Scott Lynch, Susan Mayer, Sara McLanahan, Robert Michael, German Rodriguez, seminar participants at Princeton University and The University of Chicago, and two anonymous referees for insightful suggestions made on earlier versions of this paper. I also gratefully acknowledge financial support from a Northwestern University/University of Chicago Joint Center for Poverty Research Graduate Fellowship, a Robert R. McCormick Tribune Foundation Graduate Fellowship, the Bendheim-Thoman Center for Research on Child Wellbeing at Princeton University, and the Office of Population Research at Princeton University, which is supported by center grant 5 P30 HD32030 from the NICHD. Responsible editor: Junsen Zhang.     

International migration and labor force participation of married women

A focal issue in international immigration research has been immigration adaptation and assimilation and especially absorption and integration of immigrants into labor force roles. Nevertheless, such research has largely been focused on immigrant men, neglecting the systematic examination of labor force participation among immigrant women. This research is focused on the correlates of economic activity among immigrant and native born Jewish, urban, married females aged 18–54 in Israel. The specific objectives of the investigation are: (1) the impact of education, socioeconomic status, familial child care burdens, and ethnic background on the economic activity of native-born and immigrant, married women; and (2) to evaluate the extent to which the above patterns vary by veterancy and age. The data for this analysis are drawn from Israel's quarterly labor force survey of 6,000 families for 1970 and 1971. Education, socioeconomic status, ethnic origin, and child care burden were all found to have some effect on women's labor force participation; however, the pattern of effect was different for younger and older women and varied by veterancy status. Indications can be found in the data that age at immigration, or in other words the point in the women's life cycle at which immigration occurs, makes a difference in the type and strength of effect of immigration on labor force participation.Requests for reprints should be directed to Moshe Hartman, Department of Sociology, Population Research Laboratory, Utah State University, Logan, Utah 84322.     

One Size May Not Fit All: How Obesity Among Mexican-Origin Youth Varies by Generation,Gender, and Age

Immigrants’ health (dis)advantages are increasingly recognized as not being uniform, leading to calls for studies investigating whether immigrant health outcomes are dependent on factors that exacerbate health risks. We answer this call, considering an outcome with competing evidence about immigrants’ vulnerability versus risk: childhood obesity. More specifically, we investigate obesity among three generations of Mexican-origin youth relative to one another and to U.S.-born whites. We posit that risk is dependent on the intersection of generational status, gender, and age, which all influence exposure to U.S. society and weight concerns. Analyses of National Health and Nutrition Examination Studies (NHANES) data suggest that accounting for ethnicity and generation alone misses considerable gender and age heterogeneity in childhood obesity among Mexican-origin and white youth. For example, second-generation boys are vulnerable to obesity, but the odds of obesity for first-generation girls are low and on par with those of white girls. Findings also indicate that age moderates ethnic/generational differences in obesity among boys but not among girls. Overall, ethnic/generational patterns of childhood obesity do not conform to a “one size fits all” theory of immigrant health (dis)advantage, leading us to join calls for more research considering how immigrants’ characteristics and contexts differentially shape vulnerability to disease and death.     

Towards a theory of insect epidemiology

Summary An attempt is made to consolidate and extend some of our current thoughts on insect epidemiology using graphical reproduction models. Starting with a simple model with a single equilibrium point, the elementary hypothesis is proposed that epidemics erupt when this equilibrium point increases substantially through improvement of the insect's habitat. The extension of this model to more than one coincident equilibria, some of which may be locally stable, is discussed and generalized using the theory of habitat suitability. Use of equilibrium manifolds is suggested to permit greater dimensionality. Lastly, an explanation of insect epidemics, based on the effects of time delays in the response of density-dependent processes, is elaborated and generalized. The influence of spatial dimensions and insect dispersal on the theory is discussed. Scientific Paper No. 4890, College of Agriculture Research Center, Washington State University. Modified from a paper presented at the joint meeting of the Sociedad Mexicana de Entomologia and the Pacific and Southwestern Branches of the Entomological Society of America, held at Guadalajara, Mexico, April 17–22, 1977. This work was conducted under Project 102 and was supported by the State of Washington and the National Science Foundation (Grant Nos. GB-30752 and GB-34718).     

Generational Differences in Cohabitation and Marriage in the US

We use data from pooled 2000 to 2004 current population surveys (CPSs) to examine generational differences in cohabitation and marriage among men and women ages 20–34 in the US. Consistent with our expectation and in line with assimilation theory, levels of cohabitation rise across succeeding generations. In contrast, generational differences in marriage follow a curvilinear pattern such that those in the second generation are least likely to be married, which supports some contemporary extensions of assimilation theory. These patterns persist across education groups, and tend to hold across racial and ethnic groups, too, although among women, the predicted percentages cohabiting across generations vary widely by race-ethnicity. This paper is an original work by Brown, Van Hook and Glick and is being submitted exclusively to PRPR for publication consideration. An earlier version of this paper was presented at the Annual Meeting of the Population Association of America, March 30–April 2, 2005, Philadelphia, PA.     

Residential mobility orientations of children and youth

This article addresses itself to issues in the socialization of young people to residential mobility orientations. Our conceptual framework emphasizes the importance of social context and active experience in the development of these orientations. Data from samples of youth from sixth to twelfth grades show them to have reasonable, if slightly conservative, mobility expectations. Other findings in the paper are consistent with the importance of social location and interpersonal relationships in youth socialization.The research on which this paper was based was supported by National Science Foundation Grant GS-39779. An earlier version of the paper was presented at the annual meeting of the Population Association of America, April 1974. Reuqests for reprints should be directed to Dr. Nam, Center for the Study of Population, Florida State University, Tallahassee, FL 32306.     

A dispersal-aggregation model for mountain pine beetle in lodgepole pine stands

Summary In this paper a dispersal-attack theory for bark beetle attacking trees is developed from a set of simple assumptions, and the resulting theoretical model is fit to data from four epidemic studies. Implications of the theory are discussed in relation to the dynamics of lodgepole pine-mountain pine beetle interactions. Scientific paper #4632, Project #102, College of Agriculture Research Center, Washington State university, Pullman, Washington. The work reported herein is the result of cooperation between scientists at Washington State University, the University of Idaho, and the U.S. Forest Service, and is supported by the National Science Foundation (Grant No. GB-341728), through contract SC 0024 with the University of California (Berkeley). The opinions expressed herein are not necessarily those of California or NSF.     

Factors influencing the choice of social security early retirement benefits

The present research focuses directly on the choice of early retirement Social Security benefits in 1973 for men who responded to the National Retirement History Survey. This focus is more appropriate than examining early retirement more generally when the issue is solvency of the Social Security system and appropriate changes in benefits and eligibility. While this study confirms the important role of private pensions, it tests an important concept of availability of suitable work. This factor, which proved to be a significant predictor of early beneficiary status for both blacks and whites, is critical to assumptions concerning the effect of possible changes in the age of eligibility for Social Security Early Retirement benefits. The data are also used to estimate a dramatic increase in poverty among early benficiaries and their families if these benefits were removed from their current income.This research was supported by a grant from the AARP Andrus Foundation     

Famine,revolt, and the dynastic cycle: population dynamics in historic China

Historians have long noticed that population declines in ancient China often coincided with dynasty changes, and that most of these declines were the result of internecine wars which, in turn, were often initiated by famine or density pressure. Since the interactions between density pressure, internecine wars, and dynasty changes cannot be explained by the traditional age-specific density-dependent population structure, we propose to use a bandit/peasant/ruler occupation-specific population model to interpret the dynamic socio-economic transitions of ancient Chinese population, and provide econometric support to our model. We also highlight the rich dynamics of the composition of human population, a factor which was often neglected in previous research on general populations.This research was partly funded by the Rockefeller Foundation population science grant to C. Y. Cyrus Chu. Comments and suggestions by an anonymous referee and seminar participants at Berkeley, Michigan, Stanford and National Taiwan University were helpful in the revision of earlier drafts. Generous programming help from Clint Cummins of TSP and Ruth Yu is gratefully acknowledged.     

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.