Economic growth is built on agricultural productivity in the sense that agricultural productivity is what makes it possible for workers to enter manufacturing and the service sector. This paper examines a widely underappreciated factor in the historical development of the American agricultural productivity the strengthening of property rights over time as uncertainty gave way to the issuance of federal land patents. This paper uses a model of labor supply with uncertain property rights and two data sets, newly collected farm-level data for California in 1860 and county-level data for the United States in 1860 to examine the importance of secure property rights for agricultural production in the United States. The model predicts, and we find, that individuals with weaker property rights had substantially lower agricultural output. This suggests that strengthening property rights through the issuance of federal land patents played an important role in the growth of agricultural productivity in the United States. The results have implications for our understanding of American economic history and for the development of more secure property rights in the Third World.

This paper assesses the impact of competition on racial discrimination. The dismantling of inter- and intrastate bank restrictions by U.S. states from the mid-1970s to the mid-1990s reduced financial market imperfections, lowered entry barriers facing nonfinancial firms, and boosted the rate of new firm formation. We use bank deregulation to identify an exogenous intensification of competition in the nonfinancial sector, and evaluate its impact on the racial wage gap, which is that component of the black-white wage differential unexplained by Mincerian characteristics. We find that bank deregulation reduced the racial wage gap by spurring the entry of non- financial firms. Consistent with taste-based theories, competition reduced both the racial wage gap and racial segregation in the workplace, particularly in states with a comparatively high degree of racial prejudice, where competition-enhancing bank deregulation eliminated about one-quarter of the racial wage gap after five years.

Individual US data are merged with aggregate data by state for the US and used to estimate the external benefits of education. Aggregate state-wide variables used are the average level of education and per capita physical capital for each state. Individual variables used are each working adult's labor force experience, years of completed schooling, gender and immigration status. One difference from previous studies that estimate external benefits to education is that data on physical capital for reach region (state) are available and used. Hence, the study is based on an explicit production function of the form suggested by Lucas. Strong evidence of the presence of external benefits to education for the US is found.

In the second half of the nineteenth century, some American cities adopted lead service pipes forwater delivery to homes. For some cities, this decision would have enduring negativeconsequences. Cities unlucky enough to have acidic or soft water, both of which contribute tohigh rates of lead leaching, experienced elevated infant and non-infant mortality. Using paneldata for 1900-1920, we show that in 1900, the first year for which systematic data is available,cities with lead pipes and water in the top quartiles of acidity or softness experienced infantmortality that was 12 to 23 percent higher than other cities and non-infant mortality that was 8 to20 percent higher. For a variety of reasons, these differences were close to zero by 1919. Usingcity-level panel data on value added in manufacturing for 1899-1914, we show that in 1899,controlling for the number of workers and the value of capital, these cities also had value addedthat was 9-16 percent lower. The effects were close to zero by 1914. This is consistent with leadhaving had negative health affects for working adults in these cities at the turn of the twentiethcentury.

We empirically investigate the effect of attitudes toward gays on the spread of HIV in the United States. Using a state-level panel dataset spanning the mid-1970s to the late 1990s, we find that tolerance for gays significantly decreases the HIV rate. We then investigate the causal mechanisms potentially underlying this relationship. We find evidence consistent with the theory that tolerant attitudes toward homosexuals cause low-risk men to enter the pool of homosexual partners, as well as cause sexually active men to substitute from underground, anonymous, and risky behaviors to open, socially mediated, and less risky behaviors, both of which lower the HIV rate. We consider several alternative hypotheses and conclude that they are unlikely to explain the findings. Our estimates imply that taking steps to promote tolerance may result in thousands of fewer HIV cases annually.

In this paper, we present a hybrid approach, robust principal component geographically weighted regression (RPCGWR), in examining urbanization as a function of both extant urban land use and the effect of social and environmental factors in the Twin Cities Metropolitan Area (TCMA) of Minnesota. We used remotely sensed data to treat urbanization via the proxy of impervious surface. We then integrated two different methods, robust principal component analysis (RPCA) and geographically weighted regression (GWR) to create an innovative approach to model urbanization. The RPCGWR results show significant spatial heterogeneity in the relationships between proportion of impervious surface and the explanatory factors in the TCMA. We link this heterogeneity to the sprawling nature of urban land use that has moved outward from the core Twin Cities through to their suburbs and exurbs.

Since 1990 the Hispanic population has dispersed to nontraditional places. Using Census data, this analysis documents the growth of Hispanic adolescents in new settlement areas versus traditional Hispanic metros and then carefully examines the trends in some of the basic educational outcomes of Hispanic teens. Similar to white and black youth, Hispanic teens educated in traditional Hispanic areas have improved their likelihood of completing high school. There has not been comparable progress for Hispanic youth in the new settlement areas. Controlling for the differing characteristics of Hispanics in traditional Hispanic areas versus new Latino locations attenuates the lack of progress, but it remains the case that Hispanic youth suffer a penalty from residing in a new settlementmetro. Latinos in the new settlement metros are estimated to be about 34 percent less likely to finish high school than similar Latinos in the traditional, established Latinocommunities. However, the penalty for residing in a new settlement area is not confined to Hispanic youth. NonHispanics in new settlement areas also have less favorable educational outcomes than their nonHispanic counterparts in the traditional Hispanic metros and this disparity is already apparent in 1980. Rather than an issue of immigrant adaptation per se, the subpar outcomes of Hispanic youth in their new school communities also reflect broad, long-standing geographic disparities in education.

This paper is a preliminary look at the benefits to states in the US of subsidizing college education. The benefits studies are the external benefits of college education on the earnings of both college graduates and those who have not graduated from college. In completing a college education individuals earn more. In addition, if there are positive external benefits others will also earn more because the average level of college graduates in the state has risen. This study confirms the existence of these positive externalities for the US in 2000 in estimates using the Current Population Survey. Furthermore, these external benefits are large enough that if confirmed in more complete studies would suggest that states invest too little in college education.

One versus all (OVA) decision trees learn k individual binary classifiers, each one to distinguish the instances of a single class from the instances of all other classes. Thus OVA is different from existing data stream classification schemes whose majority use multiclass classifiers, each one to discriminate among all the classes. This paper advocates some outstanding advantages of OVA for data stream classification. First, there is low error correlation and hence high diversity among OVA's component classifiers, which leads to high classification accuracy. Second, OVA is adept at accommodating new class labels that often appear in data streams. However, there also remain many challenges to deploy traditional OVA for classifying data streams. First, as every instance is fed to all component classifiers, OVA is known as an inefficient model. Second, OVA's classification accuracy is adversely affected by the imbalanced class distribution in data streams. This paper addresses those key challenges and consequently proposes a new OVA scheme that is adapted for data stream classification. Theoretical analysis and empirical evidence reveal that the adapted OVA can offer faster training, faster updating and higher classification accuracy than many existing popular data stream classification algorithms.

Are U.S. immigrants English proficiency and social outcomes the result of their cultural preferences, or of more fundamental constraints? Using 2000 Census microdata, we relate immigrants marriage, fertility and residential location variables to their age at arrival in the U.S., and in particular whether that age fell within the critical period of language acquisition. We interpret the differences between younger and older arrivers as effects of English-language skills and construct an instrumental variable for English-language skills. Two-stage-least-squares estimates suggest that English proficiency increases the likelihood of divorce and intermarriage. It decreases fertility and, for some groups, ethnic enclave residence.

Over the last twenty-five years, the homeownership rate of households 65 years and older has risen steadily, while the homeownership rate for 3564 year old households has remained relatively unchanged. At the same time, the real value of Social Security benefits has risen substantially. Using data from the March 1978 to 2001 Current Population Surveys, this paper documents the evolution and assesses the causal role of the Social Security program in increasing elderly homeownership. To isolate the causal effect, the analysis develops an instrumental-variable approach that relies on the large variation in benefits for birth cohorts from 1900 to 1930 due to double indexation of the system and the so-called Social Security notch. For all elderly, the estimated elasticity of homeownership to Social Security benefits ranges from 0.26 to 0.49. Across marital groups, the widowed have the greatest responsiveness to benefits. Increases in benefits also increase household formation among the elderly. Overall, the estimates indicate that between half and as much as all of the time-series rise in elderly homeownership over the last twenty-five years can be attributable to the rise in Social Security benefits and suggest that reductions in benefits would alter homeownership among the elderly significantly.

Census data and a semi-parametric procedure for creating counterfactual distributions are used for analyzing migration patterns between two economies with large differences in average wages, wage dispersion, and returns to education. Results show that migration flows to the United States have been composed of individuals from the middle of the distribution of skill, thus supporting a process of intermediate selection. In the other direction, higher inequality and returns to education in the island attract migrants drawn from the top of the distribution. Findings are consistent with a selectivity model where time-equivalent migration costs are large and declining in skill.

We provide new evidence on the impact of housing capital-gains taxation on homeowner behavior by examining residential mobility before and after the Taxpayer Relief Act of 1997 (TRA97), which generated the most sweeping reform of capital-gains taxation in the last two decades. In addition to lowering marginal tax rates on long-term capital gains for all assets, TRA97 also eliminated any differential treatment of housing gains above and below age 55, allowing all homeowners to qualify for capital-gains exclusions. Utilizing data drawn from the Current Population Survey (CPS) on either side of the law change (1996 and 1998) on homeowners just above (5658 year olds) and below (5254 year olds) the age-55 threshold and a reduced-form, difference-in-difference empirical approach, our estimates suggest that the repeal of the differential capital-gains tax treatment by age embodied in TRA97 had an economically important and statistically significant impact on the residential mobility of under-55 homeowners. Across a variety of specifications, the repeal raised the mobility rate by around 11.4 percentage points, which, for a mean mobility rate of 4 percentage points, represented an increase in the mobility rate of homeowners in their early 50s by 2231%. Furthermore, the bulk of this effect was concentrated among highly mobile homeowners who a priori were more likely to have wanted to trade down (e.g., divorced, empty nesters), those facing higher capital gains tax rates, and those living in states that had experienced higher rates of nominal appreciation.

This report analyzes changes among the current top five Latino nationality groups during 1990-2006 in the NYC Community District 9 of the borough of the Bronx, which comprises the neighborhoods of Parkchester, Unionport, Soundview, Castle Hill, and Clason Point. A profile of demographic and socioeconomic characteristics including population distribution, age, homeownership, income, educational attainment, employment, and citizenship is provided. These characteristics are compared, whenever appropriate, with those of the other major racial/ethnic components of the population - non-Hispanic Whites, non-Hispanic Blacks, and Asians

Using the US 5 per cent Public Use Microdata Samples (PUMS) and Census Summary Files from the year 2000, and a multilevel linear modelling strategy, this study examines the effects of a range of individual and metropolitan-area characteristics on the job earnings of US-born Whites and Blacks, foreign-born Hispanics and Asians, separately by men and women. The key findings suggest that macroeconomic structure and racial composition have significant influences on interracial and gender earnings disparities, although the direction and magnitude are different among groups. Results also show that all racial and gender groups would benefit from a more evenly distributed labour market among ethnic minorities and immigrants. With respect to gender issues, the earning gaps between racial groups are greater than between men and women. However, compared with men, women workers are more sensitive to macroeconomic conditions, racial residential segregation and labour market segmentation.

OBJECTIVE: Demographic and temporal patterns in the social and physical environments of sports and exercise in the American Time Use Survey (years 2003-2006) are described. METHOD: The sample consisted of adult respondents (ages 21+) reporting at least one bout of sports or exercise (N=8844). During the interview, participants reported where (e.g., outdoors, home, work) and with whom (e.g., alone, family, coworkers) each bout occurred. Sample-weighted multinomial logistic regression analyses estimated the adjusted proportion of bouts occurring in each environment by gender, age, education, race/ethnicity, season, weekend/weekday, and time of day. RESULTS: Among members of the oldest age group (ages 60+), more exercise bouts occurred alone and outdoors compared to younger age groups. Among college graduates, more exercise bouts occurred at a gym/health club compared to groups with lower levels of education. Exercise bouts occurring alone were most likely to happen in the winter, on weekdays, and in the morning. Exercise bouts occurring outdoors were most likely to happen in the summer, on weekend days, and in the morning. CONCLUSION: Future research and intervention efforts exploring where, when and with whom exercise bouts occur may prove beneficial to addressing public health concerns about physical inactivity.