Different soil classes offered varying economic results for farmers. The use of multiple data sets to analyze the connection between soils, economic benefits, and settlement patterns at three geographical levelsthe five states of the Old Northwest, the sixty-eight counties in Michigan's Lower Peninsula, and the individual farms in one mid-Michigan countytends to confirm that soils were a significant motivating factor in the locational decisions of antebellum farmers at the state, county, and intra-county levels of the north-central United States during the mid-nineteenth century.

Gender-typical educational choices and the “glass ceiling” are widely believed to explain why older women earn far less than observably similar men. Using large panels drawn from the National Science Foundation's (NSF) National Survey of College Graduates and other data representative of U.S. college graduates from the 1990s, the author documents the small role of personal choices and finds evidence contrary to the predictions of both human capital and discrimination models. Rather than the differential wage growth rates predicted by these models, she finds similar average rates of earnings growth for women and men across numerous specifications, which suggests that the gender gap in earnings is determined by factors already present early in the career. Her findings reveal slower earnings growth in only two subsets of women: young mothers, who experience slower earnings growth during the early career relative to men the same age, but then compensate with faster growth later in their careers; and women with exceptionally high earnings levels. The latter are underrepresented among workers winning the largest promotions, when compared to similarly successful men the same age, and face a glass ceiling at the very top of the career ladder.

The purpose of data mining from distributed information systems is usually threefold: (1) identifying locallysignificant patterns in individual databases; (2) discovering emerging significant patterns after unifyingdistributed databases in a single view; and (3) finding patterns which follow special relationships across differentdata collections. While existing research has significantly advanced the techniques for mining local and global patterns (the first two goals), very little attempt has been made to discover patterns across distributed databases(the third goal). Moreover, no framework currently exists to support the mining of all three types of patterns. Thispaper proposes solutions to discover patterns from distributed databases.More specifically, we consider patternmining as a query process where the purpose is to discover patterns from distributed databases with patterns' relationships satisfying user specified query constraints. We argue that existing self-contained mining frameworks are neither efficient, nor feasible to fulfill the objective, mainly because their pattern pruning is single-database oriented. To solve the problem, we advocate a cross database pruning concept and propose a collaborative pattern (CLAP) mining frame work with cross-database pruning mechanisms for distributed pattern mining. In CLAP, distributed databases collaboratively exchange pattern information between sites so that each site can leverage information from other sites to gain cross-database pruning. Experimental results show that CLAP fits a niche position, and demonstrate that CLAP not only outperforms its other peers with significant runtime performance gains, but also helps find patterns incapable of being discovered by others.

This poster illustrates the spatial diffusion of whites from the city center of Birmingham, Alabama, following the Civil Rights Movement using census data from 1960 through 2010. Spatializing race data by averaging a tracts adjacent polygon values allows us to visualize two segregation indicesthe Dissimilarity Index (Di) and the Exposure Index (Si*)at the census tract level, while minimizing the modifiable areal unit problem (MAUP). The resultant maps are paired and critiqued alongside county-wide segregation index values, revealing the limitations of lumped calculation alone in understanding changes in patterns of segregation over time. This modified approach visualizes the trajectory underlying the shift from de jure to de facto segregation in Birmingham in an effort to reveal how the dominant habitus initiated a spatial reconfiguration minimizing white exposure to the challenges to habitus intended by de jure desegregation.

A growing literature seeks to explain why so many more women than men now attend college. A commonly cited stylized fact is that the college wage premium is, and has been, higher for women than for men. After identifying and correcting a bias in estimates of college wage premiums, I find that there has been essentially no gender difference in the college wage premium for at least a decade. A similar pattern appears in quantile wage regressions and for advanced degree wage premiums.

During the twentieth century millions of African Americans migrated from the Southern United States to the North and West. Over the same period, significant gains in education were made that brought the educational attainment of southern blacks more in line with that of their northern counterparts. Much of the literature on the relationship between the Great Migration and schooling has focused on the educational characteristics of the migrants. In contrast, this study considers how the Great Migration affected the educational demands of southern blacks. Using the IPUMS, this study analyzes the impact of the increased probability of migration during this period on the school attendance of southern African Americans. The findings show that a 10 percentage point increase in the probability of migration caused the probability of attending school to increase by 2.8 to 3.4 percentage points.

It is often asserted that the gender gap in educational attainment is larger for blacks than whites, but historical trends comparing the black and white gender gap have received surprisingly little attention. Analysis of historical data from the U. S. census IPUMS samples shows that the gender gap in college completion has evolved differently for whites and blacks. Historically, the female advantage in educational attainment among blacks is linked to more favorable labor market opportunities and stronger incentives for employment for educated black women. Blacks, particularly black males, still lag far behind whites in their rates of college completion, but the striking educational gains of white women have caused the racial patterns of gender differences in college completion rates to grow more similar over time. While some have linked the disadvantaged position of black males to their high risk of incarceration, our estimates suggest that incarceration has a relatively small impact on the black gender gap and the racial gap in college completion rates for males in the United States. 2011 Population Association of America.

The process of intelligent query answering consists of analyzing the intent of a query, rewriting the query based on the intention and other kinds of knowledge, and providing answers in an intelligent way. Producing answers effectively depends largely on users knowledge about the query language and the database schemas. Knowledge, either intentional or extensional, is the key ingredient of intelligence. In order to improve effectiveness and convenience of querying databases, we design a systematic way to analyze users request and revise the query with data mining models and materialized views. Data mining models are constrained association rules discovered from the database contents. Materialized views are pre-computed data. This paper presents the knowledge acquisition method, its implementation with the Erlang programming language, and a systematic method of rewriting query with data mining models and materialized views. We perform efficiency tests of the proposed system on a platform of deductive database using the DES system. The experimental results demonstrate the effectiveness of our system in answering queries sharing the same pattern as the available knowledge.

I examine the contested finding that men and women engage in gender performance through housework. Prior scholarship has found a curvilinear association between earnings share and housework that has been interpreted as evidence of gender performance. I reexamine these findings by conducting the first such analysis to use high-quality time diary data for a U.S. sample in the contemporary period. Drawing on data on 11,868 married women and 10,770 married men in the American Time Use Survey (20032007), I find no evidence that married men do gender through housework. I do, however, find strong evidence of gender performance among women as evidenced by a curvilinear association between earnings share and women's housework time.

Education emerged, over the course of the twentieth century, as America’s key to opportunity and one of the main arbiters of success (Fischer and Hout 2006; Goldin and Katz 2007). For individuals, education is a human capital investment that improves the quality of life. For American society, equality of educational opportunity is an oft-stated goal. Equality of educational opportunity serves as a measure of the nation’s progress toward fairness.

Purpose – Our ultimate goal is to characterize three methodological issues. First, compare the relative performance of alternative estimation methods for long time series, second, estimate the degree of correlation between effort and circumstances, and, third, decompose total inequality into inequality of opportunity and inequality of effort according to an ideal tree. Methodology – We estimate parametrically and nonparametrically the ex-ante inequality of opportunity in the United States between 1969 and 2007. The degree of correlation between effort and circumstances is computed following the proposal in Björklund et al. (2011). In addition, we decompose total inequality based on an ideal tree with three levels of disaggregation by applying the natural decomposition of the squared coefficient of variation and the Nested Shapley value. Findings – We find significant differences between the nonparametric and parametric approaches. In particular, our results reveal that considering cross-effects between circumstances may be relevant. Moreover, the degree of correlation between effort and circumstances which has significantly increased over the period 1969 and 2007 in the United States, explains between 5% and 20% of total IO. In addition, race is the main circumstance during the 1970s and 1980s, accounting for more than 50% of the direct IO, while parental education take the lead in the last two decades. Originality – We modify the parametric specification by considering cross-effects between circumstances. We estimate the degree of correlation between effort and circumstances for long time series. We decompose total inequality according to a three-level hierarchical model.

The United States contains an enormous variety of racial and ethnic groups, many of which have faced discrimination, both historically and today. My dissertation studies how minority races and ethnic groups were (and are) treated differently and how these treatments affect economic outcomes from different angles, including income, education, employment and health. Historically, blacks were denied access to many hospitals because of their race. Chapter One uses a historical natural experiment—federally-mandated hospital desegregation—to study the impact of access on racial differences in deaths from motor vehicle accidents. Focusing primarily on Mississippi, I use detailed micro-data from the US Vital Statistics matched with race-specific hospital survey information. Combining this data set with a race-specific distance to the nearest hospital before and after integration, I find that, on average, distance to nearest hospital fell by 50 miles for blacks after integration. I also show that distance and accident mortality were positively correlated: increases in distance to the nearest hospital were associated with higher mortality. Chapter Two focuses on a contemporary issue—Racial and ethnic differences in medical utilization. I focus on the heart failure because it is the leading noncancerous diagnosis for patients in hospice care and the leading cause of hospitalization among Medicare beneficiaries. In a national sample of Medicare beneficiaries with heart failure, I find that blacks and Hispanics used hospice care for heart failure less than whites after adjustment for individual and market factors. Blending both historical and contemporary analysis, Chapter 3 studies a previously unnoticed trend—a secular decline from 1960 to 2000 in the relative likelihood that Asian-Americans worked in the public sector. In 1960 Asian Americans were nearly ten percentage points more likely to work in the public sector than were Whites, but by 2000 the gap had declined to two percentage points. I argue that this relative decline in public employment reflects relative improvement over time in labor market outcomes in the private sector for Asian Americans.

Women now attain bachelor's and graduate degrees at rates that equal or exceed mens. Despite this progress, sex segregation in fields of study persists. Men are more likelythan women to major in science, particularly physical science and engineering, and data indicate that gender convergence among science majors is not likely in the near future. Explanations for the persisting shortfall of women in the physical sciences and engineering must account for broader trends in education and the consequences of women's major choice for their careers and family lives. Using data from the 1980 to 2000 Census and the 2009 American Community Survey, we analyze trends over time inhighly-educated women's occupational choices and the consequences of their choices in terms of marriage, fertility and earnings. Womens career choices, especially in highstatus, demanding occupations in the sciences, have consequences for all three outcomes.

The seemingly wide opening for liberal domestic policy innovation by the U.S. federal government in theearly-to-mid-1930s gave way to a much more limited agenda in the late 1930s and 1940s. The latter yearssaw the consolidation and gradual extension of several key programs (e.g., Social Security and Keynesianmacroeconomic management), but also the frustration of liberal hopes for an expansive cradle-to-gravewelfare state marked by strong national unions, national health insurance, and full employment policies.Drawing upon rarely used early public opinion polls, we explore the dynamics of public opinion regardingNew Deal liberalism during this pivotal era. We argue that a broadly based reaction against labor unionscreated a difficult backdrop for liberal programmatic advances. We find that this anti-labor reaction wasespecially virulent in the South but divided even Northern Democrats, thus creating an effective wedge issuefor Republicans and their Southern conservative allies. More generally, we find that the mass public favoredmost of the specific programs created by the New Deal, but was hardly clamoring for major expansions of thenational governments role in the late 1930s and 1940s. These findings illuminate the role played by theSouth in constraining New Deal liberalism while also highlighting the tenuousness of the liberal majority inthe North.