Although considerable developments in automated generalization have taken place over the last thirty years, it is still difficult to solve generalization problems with off-the-shelf software due to the limited capability of the algorithms and complexity of the databases. At the National Historical Geographic Information System (NHGIS) project at the University of Minnesota (http://www.nhgis.org/), work is currently underway to design a multiple scale database at1:150,000, 1:400,000, and 1:1,000,000 through the application of data models and generalization algorithms.The NHGIS is taking a two-fold approach using both specific algorithmic approaches and object-oriented datamodeling. Early results from the application of a mixture of standard and custom-tailored algorithms such as theDouglas and Visvalingham routines has shown promising results, especially along coastal areas. Examples of coastalgeneralization at a variety of scales are provided. The project will continue to develop the needed generalizationalgorithms as specific geographical conditions are encountered. Current work is identifying the specific constraints such as distance between points and/or objects and specific algorithms needed for generalization at the various scales and applying these in a comprehensive generalization framework that goes beyond the tract boundary specific approach.

This paper investigates as part of the National Historical Geographic Information System project(http://www.nhgis.org/) the creation of a multi-scale database of historical US census units. Thisdatabase will include, at a minimum, three different scales (1:150,000, 1:400,000 and 1:1,000,000)and boundary data for all documented census since 1790. Besides the commitment to the productionneed, the main challenge in the generalization of these spatio-temporal data is the maintenance ofgeometric and topological consistency both within a dataset and between datasets for one target scale.We propose to address this challenge through: (1) a generalization framework based on the constraintbasedgeneralization paradigm and the active object approach; and (2) a topological data modellinking all datasets, which represent different census years, for one target scale. The framework isimplemented in ESRIs ArcGIS environment using ArcGIS 9.0, Oracle, C# and ArcObjects. Theimplementation of the model generalization process was completed and successfully tested for thethree target scales of the final database. Model generalization accomplishes the removal of redundantpoints and the removal of boundary-change sliver polygons. The implementation of the cartographicgeneralization process is still on-going and has focused, until recently, on different approaches for theenlargement and elimination of too small census units or detached parts of a census unit as well as onthe reduction of the outline granularity of census units boundaries. Results that were automaticallygeneralized with the current version of the prototype exhibit satisfying quality based on a preliminaryvisual evaluation.

Status-caste exchange theory predicts that in interracial marriages one partner's socioeconomic status is exchanged for the other's racial caste status. The author examines the contradictory literature on the theory specifically in relation to black-white intermarriage and offers three explanations for the divergent findings. First, black-white inequality has obscured the actual status homogamy typifying intermarriage. Second, gender differences among young couples have been mistaken for racially specific patterns of exchange. Third, the empirical findings that appear to support status-caste exchange are not robust. The author's conclusions favor the simplest tabular analyses, which cast doubt on status-caste exchange theory

In this paper I redefine the concept of sexual revolution and suggest two new measurements for the process. I review prior definitions and measurements of sexual revolution. I redefine sexual revolution in response to a Victorian script linking the public statuses of marriage and childbearing to the privacy of sexual experience. I measure sexual revolution as resistance to this script. In particular, women break the link between sex, marriage, and childbearing, and make sexual behavior public by being wives without children or being mothers without ever marrying. I demonstrate the historical relevance of these measurements in the United States by using IPUMS census data from 1880-2000. I compare metropolitan and nonmetropolitan populations, black and white populations, and the populations of four metropolitan areas (Boston, Richmond, Indianapolis, and San Francisco) with respect to sexual revolution. The results indicate that these new measurements of sexual revolution both correspond with and confirm past research on sexual revolution and point towards the possibility of further research. . .

During the last forty years of U.S. experience, the proportion of two earner couples in all married couples increased from 30% to 70%. During the same period, tax laws have undergone numerous changes, with major reforms taking place in the 1980s that effectively flattened the tax schedule. Did changes in tax laws make secondary earners more prone to work? We use a model of heterogeneous agents with discrete work choice in order to quantitatively assess the impact of income tax reforms on the observed patterns of married couples labor supply. Tax Simulator Software provided by NBER is used in conjunction with IRS Income Statistics to compute income and FICA taxes three times for each couple in the model: once when only the husband works, second when only the wife works, and third when both work. These calculations are used jointly with a model of family decision making to determine family labor supply for each prototypical couple in the data. Our main finding is that changes in tax laws account for 30% of the increase in the proportion of two earner couples in the 1980s but cannot account for the observed patterns in the other decades. Interestingly, we discover that the introduction of the Earned Income Tax Credit drives some of the observed changes in the pattern of wives hours by husbands income, in particular, the positive correlation of wives hours and husbands income for low levels of husbands income.

This article explores the labor market status of older males in the early twentieth century, focusing on how the extent of pressure toward retirement differed across occupations and how it changed over time. A comparison of the probability of retirement across occupations shows that men who had better occupations in terms of economic status and work conditions were less likely to retire than were those with poorer jobs. The difficulty faced by older workers in the labor market, as measured by the relative incidence of long-term unemployment, was relatively severe among craftsmen, operatives, and salesmen. In contrast, aged farmers, professionals, managers, and proprietors appear to have fared well in the labor market.The pattern of shifts in the occupational structure that occurred between 1880 and 1940 suggests that industrialization had brought a growth of the sectors in which the pressure toward departure from employment at old ages was relatively strong.

Philadelphia is a big city with big city challenges and big city opportunities. It declined badly in the 1970s in population, in production, in measures of prosperity and wealth, possibly in social cohesion as well, but has stabilized or rebounded since then. Racial tension, poverty, and inequality are severe challenges within the citys economy and social structures. Increasing disparity between the city and suburbs is a disturbing trend, though it is also the norm among US metro areas. The economy is diverse, with important industrial concentrations in management, finance & insurance, and professional services. The shift-share analysis suggests these same industries have been fairly steady within the regional economy in recent years. Occupational clusters are also present in several high-paying occupational groupings, including community and social services; life, physical, and social sciences; healthcare; management; and computer and mathematics occupations. Economic development professionals would do well to guard those industries and occupational categories in the region and build on them as opportunities arise. Philadelphias industrial base in manufacturing continues to erode, with no end in sight to this trend.

How did the wartime health of Union Army recruits affect their wealth accumulation through 1870? Wounds and exposure to combat had strong negative effects on subsequent savings, as did illnesses while in the service. The impact of poor health was particularly strong for unskilled workers. Health was a powerful determinant of nineteenth-century economic mobility. Infectious diseases' influences on wealth accumulation suggest that the economic gains from the improvement of the disease environment should be enormous. The direct economic costs of the Civil War were probably much greater than previously thought, given the persistent adverse health effects of wartime experiences.

The rise of cohabitation in the United States in the late twentieth century is an important component of the dramatic changes in marriage, family formation and childbearing (e.g., Bumpass, Sweet and Cherlin 1991; Bumpass and Lu 2000; Casper and Bianchi 2002; Manning 1995). This increase, first noted in the 1970s, was initially inferred from household composition because few data sources collected direct information on couples “living together” (Glick and Norton 1977, Glick and Spanier 1980). Research on cohabitation exploded in the 1980s as the trend accelerated and when longitudinal data sources, such as the National Survey of Families and Households, provided nationally representative datasets designed . . .

The past century has witnessed a rapid rise in life-expectancy and a sharp fall in labor force participation rate (LFPR) of older males. At the beginning of this century, life-expectancy of males at age twenty was less than 42 years (Preston, Keyfitz, and Scheon 1972, 724), while it was longer than 53 years in 1990 (U.S. Department of Health and Human Services 1992a, 34). A century ago, 65 percent of males aged sixty-five or older were in the labor force (Moen 1987a); only 15 percent of men in the same age group participated in the labor force in 1993 (U.S. Bureau of the Census 1994, No. 615). The average duration of retirement should have increased over time as people retired earlier and lived longer than before on average....

We show that incorporating consumption commitments into a standard model of precautionary saving can complicate the usual relationship between risk and consumption. In particular, we present a model where the presence of plausible adjustment costs can cause a mean-preserving increase in unemployment risk to lead to increased consumption. The predictions of this model are consistent with empirical evidence from dual-earning couples. Couples who share an occupation face increased risk as their unemployment shocks are more highly correlated. Such couples spend more on owner-occupied housing than other couples, spend no more on rent, and are more likely to rent than own. This pattern is strongest when the household faces higher moving costs, or when unemployment insurance provides a less generous safety net.

Using multiple births as an exogenous shift in family size, I investigate the impact of the number of children on child investment and child well being. Using data from the 1980 US Census Five-Percent Public Use Micro Sample, 2SLS results demonstrate that parents facing a change in family size reallocate resources in a way consistent with Becker’s Quantity & Quality model. A larger family generated by a twin on a later birth reduces the likelihood that older children attend private school, reduces the mother’s labor force participation, and increases the likelihood that parents divorce. The impact of family size on measures of child well being, such as educational attainment is less clear. The results indicate that for both measures of child investment and child well being, the 2SLS estimates are statistically distinguishable from OLS estimates indicating an omitted variables bias in the single equation model.

Racial residential segregation is most often expressed with an index conveying the unevennessof settlement across census tracts. Despite small declines in the unevenness of black-whitesettlement in some U.S. cities, it is less clear what this says about segregation, integration, orrace relations. This paper discusses the limitations of indices of residential segregation andoutlines a range of approaches emphasizing the multiple boundaries that impede interracialcontact and privilege access to resources. A more complete understanding of the state of racerelations requires an array of methods to systematically examine the physical, social, andpsychological boundaries that influence social integration and segregation. Birds-eyeapproaches focus on boundaries across communities in a city to generalize about settlementpatterns. Segregation indices fit into this tradition, depicting patterns of proximity but sayingnothing about actual interaction or ties. Ground-level approaches look more closely withindiverse communities at how residents form associations and why. I argue that a clearer pictureof segregation will emerge if we retool how we use indices of segregation and if we complementit with other approaches.

This dissertation examines the changing relationships between education, income, and marital status for men and women between 1940 and 2000, linking these changes to shifts in economic, social, and family life. The findings suggest that in the early part of period, when gender specialization in work and family life was more prevalent, high education levels impeded marriage for women. However, the relationship between education and marriage reversed as women entered the workforce in large numbers, education levels expanded, and work became a normative part of womens lives. I call this reversal of the relationship between education and marriage for women the marriage gradient transition. This transition occurred earlier for Black women than for White women, likely as a result of Black womens earlier entry into the labor force en masse and higher wages relative to Black men. While economic status became a more important determinant of womens marriage over the period, it in importance for mens marriage. This suggests that mens non-economic characteristics, such as willingness to participate in housework and child-rearing, may have become more important considerations in marriage decisions. Overall, I find little support for the independence, marriage gradient hypotheses and some support for the male economic status hypothesis. Although these theories differ with regard to whose income or education matters in the transition to marriage, they all make a similar pointthat the increasing rate of non-marriage (or age at marriage) over time is a result of the changing characteristics of the population rather than a fundamental change in the relationship between income/education and marriage. I suggest an alternative approach, which I call the gender revolution theory. This theory suggests that the connection between economic status and marriage may have been transformed as the historical context in which young adults make decisions about marriage changed. As womens education, employment, and income patterns have become increasingly similar to mens, the relationship between economic status and marriage may become more similar for men and women. Women may also use their increased bargaining power to select marriage partners based on favorable non-economic characteristics such as gender ideology or housework participation.

The field of demography (also referred to as population studies) has evolved significantly since the mid-twentieth Century. A useful benchmark for gauging the nature andextent of change of the field is Hauser and Duncans landmark work, The Study of Population: An Inventory and Appraisal, published in 1959. The 33 chapters contained inthat volume were grouped into four sections. Part I, Demography as a Science, contained four chapters laying out the substantive, methodological, epistemological, and organizational foundations of the discipline (Hauser and Duncan 1959a, 1959b, 1959c, 1959d). Part II, Development and Current Status of Demography, offered eight chaptersportraying the origins and practice of demography in selected nations, along with an insightful overview of disciplinary history (Lorimer 1959). Part III, Elements ofDemography, included a dozen chapters covering elements of the demographic equation(structure and components of change), as well as assessments of demographic data. Finally, Part IV, Population Studies in Various Disciplines, contained seven chaptersdiscussing common interests of demography and selected disciplines, including sociology (Moore 1959), economics (Spengler 1959), and human ecology (Duncan 1959). See the Epilogue to this Handbook by Poston, Baumle, and Micklin for more discussion.

Their numbers in mid-nineteenth century New York suggest that the city acted as a kind of irresistible magnet for Irish immigrants. Contemporary commentary cited the lure of friends and community, but also counselled immigrants against clinging to the east coast cities. Throughout the 1850s, but particularly at times of high unemployment such as in 1854-5 and in the wake of the Panic of 1857, philanthropists, labour and ethnic activists, and the local press urged the westward movement of labour. In June 1855 the New York Times even called on the city to finance such movement. Irish newspapers such as the Citizen and the Irish-American also advised people to move. In the wake of the financial panic of October 1857 Irish philanthropist Vere Foster prevailed on the Women’s Protective Emigration Society to pay for the westward journey of about . . .

With accelerated world market integration, cities compete with each other cities as sites of production and consumption, targeting firms and households as semi-autonomous location decision-makers. Distinction may be sought in productive structure, consumption and identity. In this paper, contradictory trends towards homogenisation and distinctiveness are theorised. Studying the occupational structure of 50 large US metropolitan areas, it is found that distinctiveness has been increasing in economic base occupations though some heavily blue-collar cities edge is eroding. Employment in consumption activities has been growing faster than in the economic base and cities are becoming more alike in consumption structure. It is concluded that the search for niches in exporting sectors and related occupational mix is key to urban resurgence.

Interracial unions and same-sex unions were rare and secretive in the past because US. society was organized to suppress such unions. The rise of same-sex and interracial unions in the past few decades suggests changes in the basic structure of US. society. Young adults have been marrying later and single young adults are much less likely to live with their parents. The independence of young adults has reduced parental control over their children choice of mate. Using microdata from the US. Census, this article shows that interracial couples and same-sex couples are more geographically mobile and more urban than same-race married couples. The authors view the geographic mobility of young couples as a proxy for their independence from communities of origin. The results show that nontraditional couples are more geographically mobile even after individual and community attributes are taken into account. Same-sex couples are more likely to be interracial than heterosexual couples, indicating that same-sex and interracial couples are part of a common fabric of family diversification. The article discusses related historical examples and trends