Thunderstorms frequently produce brief flooding or minor damage, though far fewer lead to major floodingand widespread or significant damage. Outbreaks of such storms exact large tolls on their victims and cancompromise, or completely overwhelm, the emergency response infrastructure. This paper derives empiricalfrequencies and recurrence intervals of high end convective weather events in the MinneapolisSt. Paul,Minnesota, metropolitan area from archived tornado, hail, damaging-wind, and high-density daily rainfalldata, as well as historical records and accounts. Two classes of high-impact events are analyzed: those with thepotential to produce widespread damage or disruption and those virtually certain to do so. Storms in this firstclass recur within the area, on average, 3 times per year, while the more extreme storms recur every 22.5 yron average. Owing to well-established spatial and temporal inhomogeneities in observed severe weather data,true recurrence intervals are probably somewhat shorter. In the context of ongoing regional populationgrowth, the area is becoming increasingly vulnerable to major damage and potential casualties from thesemajor storm events.

When I arrived home that night, I found my mother sobbing uncontrollably on the floor. She collected herself enough to tell me that they had taken Augie, my younger brother, away in handcuffs; that he was a suspect in a murder. I was a freshman in college at the time. I didn't know what to do. I didn't know whom to turn to. We were powerless in enforcing our rights or Augie's rights, and we were at a complete loss for words., Latinos are invariably affected by many of the same legal issues that arise among the U.S. population at large. Indeed, in 1994, Augustin Torres-Linares was arrested and criminally prosecuted under procedures that most defendants and their families face in similarly-situated cases. Yet, the experience affects the Latino individual, and especially the Latino family, in ways it generally does not affect the American mainstream. The legal system is currently being tested through its response to the growing needs of the Latino population, particularly in the Chicago metropolitan area, where there has been an . . .

The negative correlation between female employment and fertility in industrialized nations has weakened since the 1960s, particularly in the United States. We suggest that the continuing influx of low-skilled immigrants has led to a substantial reduction in the trade-off between work and childrearing facing American women. The evidence we present indicates that low-skilled immigration has driven down wages in the U.S. child-care sector. More affordable child-care has, in turn, increased the fertility of college graduate native females. Although childbearing is generally associated with temporary exit from the labor force, immigrant-led declines in the price of child-care have reduced the extent of role incompatibility between fertility and work.

Since 1950, U.S. educational attainment has increased substantially. While the median student in 1950 dropped out of high school, the median student today attends some college. In an environment with ability heterogeneity and positive sorting between ability and school tenure, the expansion of education implies a decrease in the average ability of students conditional on school attainment. Using a calibrated model of school choice under ability heterogeneity, we investigate the quantitative impact of rising attainment on ability and measured wages. Our findings suggest that the decline in average ability depressed wages conditional on schooling by 31-58 percentage points. We also find that the entire rise in the college wage premium since 1950 can be attributed to the rising mean ability of college graduates relative to high school graduates.

This paper studies the role of endogenous human capital accumulation in evaluating tax and SocialSecurity policies. It considers two overlapping generations environments with borrowing constraints:one with exogenous human capital and a second with human capital accumulation through timeinvestment. Baseline environments are calibrated to the U.S. tax and Social Security system. Thispaper analyzes two alternative Social Security systems: (a) voluntary and (b) mandatory retirementsavings accounts. The paper finds that the welfare ranking of these alternatives depends on the endogeneityof human capital investment. Both systems are welfare improving when compared to thebaseline. However, the system with mandatory (voluntary) accounts leads to lower welfare gainsin the endogenous (exogenous) human capital environment. This difference is due to young individuals(i) switching time allocation towards human capital accumulation and (ii) being borrowingconstrained under mandatory savings in the endogenous environment.

This paper examines the effects of low-skilled immigration on the work andfertility decisions of high-skilled women born in the United States. The evidencewe present indicates that low-skilled immigration to large metropolitan areas between1980 and 2000 lowered the cost of market-based household services. Usinga novel estimation technique to analyze joint decision making, we find thatcollege-educated native females responded, on average, by increasing fertility andreducing short-run labor force participation. These changes were accompanied bya weakening of the negative correlation between work and fertility, as well as anincrease in the proportion of women who both bore children and participated inthe labor force. Taken in combination, our estimates imply that the continuinginflux of low-skilled immigrants substantially reduced the work-fertility tradeofffacing educated urban American women.

The present research analyses the ‘social visualization’ tool Sense.us, a commercial interactive Web application in which U.S. Census data are visualized. Sense.us was developed as a tool for social data exploration and interaction, in which it would be worthwhile to pay attention to the socio–cultural values that have driven the collection and categorization of the underlying U.S. Census datasets. It is argued that closer attention to value driven U.S. Census statistics would greatly enhance the social appeal of Sense.us, and would be a logical next step in the development of online social visualization tools. In order to allow for explicit socio–cultural values of statistics in online visualizations, three strategies are offered: pro–active annotation; more attention to visual aesthetics; and, a tighter integration of user profiles and represented data.

In this paper, we quantify the effects of health on time allocation. We estimate that improvements in health status have large and positive effects on time allocated to home and market production and large negative effects on time spent watching TV, sleeping, and consuming other types of leisure. We find that poor health status results in about 300 additional hours allocated to unproductive activities per year. Plausible estimates of the cost of this lost time exceed $10,000. We also find that, for men, better health induces a substitution of market-produced goods for home-produced goods. Particularly, each additional minute spent in home production saves $0.37.

This article offers a basic understanding of the characteristics of older immigrants as compared to the U.S.-born population. This includes age and sex structure, marital status, time in the United States, origin and geographic distribution. The article distinguishes between long-time immigrants (older, more European, more assimilated -- more apt to speak English) and newcomers (younger, Asian or Hispanic, less assimilated).

After 1994, the homeownership rate in the USA departed from its historical secular pattern and increased from 64.0 percent in that year to a peak of 69.0 percent in 2004. Although it is currently trending down, the US homeownership rate is still above the levels recorded before 1998. This chapter summarizes its history and explains what factors are behind its recent behavior.

ABSTRACT. Between 1880 and 1930, the employment rate of children ages 10 to 15 decreased by over 75% inthe U.S. economy. During this period, several U.S. states dictated state-wide child labor legislation that imposedminimum age restrictions for employment in the manufacturing sector. The objective of this paper is to characterizewhether this child labor legislation contributed to the decline in children labor market participation.Previous literature on this topic, such as Moehling [10] and Moehling [11], has utilized dierence-in-dierenceestimation techniques to study the eectiveness of the child labor legislation in reducing child labor. We contributeto this literature in two ways. First, we show that, under the presence of general equilibrium eects such as the onesdescribed by Basu and Van [3], dierence-in-dierence estimation techniques can provide a misleading measure ofthe eectiveness of the legislation. Second, in addition to evaluating whether the legislation was eective or not,we analyze the labor market mechanism by which this takes place. This analysis may allow us to establish if thelegislation constituted a benign policy or not, that is, whether the legislation imposed constraints to the behaviorof children (not benign) or whether it generated a change in labor market equilibrium (benign).We ?nd that child labor legislation was eective in reducing general employment levels for boys and girls. Moreover,we ?nd that the legislation was benign for general employment level for girls. We also show that the legislationwas ineective in reducing child labor participation in the manufacturing sector.

This paper describes trends in average weekly hours of market work per person and per family in the United States between 1950 and 2005. We disaggregate married couple households by skill level to determine if there is a pattern in the hours of work by wives and husbands conditional on either husband's wages or husband's educational attainment. The wage measure of skill allows us to compare our findings to those of Juhn and Murphy (1997), who report on trends in family labor using a different data set. The educational measure of skill allows us to construct a longer time series. We find several interesting patterns. The married women with the largest increase in market hours are those with high-skilled husbands. When we compare households with different skill mixes, we also find dramatic differences in the time paths, with higher skill households having the largest increase in average hours over time.

The social integration of immigrants is believed to be an important determinant of immigrants labor market outcomes. Using 2000 U.S. Census data, we examine how andwhy marriage to a native, one measure of social assimilation, affects immigrant employment rates. We show that even when controlling for a variety of human capitaland assimilation measures, marriage to a native increases the probability that an immigrant is employed. An instrumental variables approach which exploits variation inmarriage market conditions suggests that the relationship between marriage decisions and employment rates is not likely to arise from positive selection into marrying a native.We then present several pieces of evidence suggesting that networks obtained throughmarriage play an important part in explaining this effect.

The present research seeks to shed light on change in the dynamics of Mexican migration to the United States and settlement processes in the 1990s, a time of tremendous growth in Mexican migration flows and greater geographic diversity in migrant destinations. Specifically, the investigation that follows assesses: (1) change in the kinds of migration flows within which male and female migrants arrive in the United States; (2) whether settlement in newer destinations of Mexican migration indicate change in male/female migration processes; and (3) the extent to which such settlement diverges from traditional patterns of male and female Mexican migration and whether the role that gender plays has changed.

Data mining is one of the most exciting information science technologies in 21 century. Contrast patterns mining is one of the most challenging and vital techniques in data mining research. Patterns, or groups, are collections of items which satisfy certain properties which are of interesting information (Ramamohanarao et al, 2005). Contrast patterns of various kinds differ greatly, for example, Pattern and rule based contrasts, Data cube contrasts, Sequence based contrasts, Graph based and Model based contrasts. However, there is no one specific paper or research lays the emphasis on comparing the similarities and differences between them.This research, therefore, is intended to

1. Introduction: Historical GIS and National Historical GIS databasesHistorical Geographical Information Systems, or Historical GIS, has become a rapidly growing field within historical research (Gregory & Ell 2007; Gregory & Healey 2007; Knowles 2005). It is an inter-disciplinary field that involves taking GIS technology, devised in the fields of computer science and environmental management, and applying it to the study of history. A major impetus behind the growth of Historical GIS has been the significant investments made by a number of countries in National Historical GISs (NHGIS). Typically, these databases contain a countrys census reports and other data for the nineteenth and twentieth centuries, including both the statistical data linked to specific administrative units and their geographic locations, together with the changing boundaries of those units. Using a traditional census database containing only statistical information, a researcher could search for aspatial patterns of variation and change across units unattached to their real geographic locations. Using an historical GIS, however, the researcher is now equipped to identify patterns of change that occur simultaneously over time and across geographic space. With historical GIS we can get closer to complexity of change and historical reality.Among the countries that have built or are building NHGISs, the best developed include Great Britain (Gregory et al. 2002), the United States (Fitch & Ruggles 2003), and Belgium (De Moor & Wiedemann, 2003).1. Such systems are costly because they require not only the entry of census information but also the researching and encoding of administrative boundary changes through time, not to mention myriad challenges along the way.2Is all the effort and money expended worth the cost? This paper offers a strong affirmative answer in two ways. Using the Great Britain Historical GIS as an example of highly developed national historical GISs, this paper describes how it was built and1illustrates both the analytic approaches and the substantive results that historical GIS enables. Computer-assisted GIS is not the philosophers stone of course. But it is capable making new contributions to our knowledge of the past, all the more so when combined with other tools in the historian/historical geographers kit.

here are nearly 20,000 general-purpose municipal governmentscitiesin the United States, employing more people than the federal government. About twenty of those cities received charters of incorporation well before ratification of the U.S. Constitution, and several others were established urban centers more than a century before the American Revolution. Yet despite their estimable size and prevalence in the United States, city government and politics has been a woefully neglected topic within the recent study of American political development.The volume brings together some of the best of both the most established and the newest urban scholars in political science, sociology, and history, each of whom makes a new argument for rethinking the relationship between cities and the larger project of state-building. Each chapter shows explicitly how the American city demonstrates durable shifts in governing authority throughout the nations history. By filling an important gap in scholarship the book will thus become an indispensable part of the American political development canon, a crucial component of graduate and undergraduate courses in APD, urban politics, urban sociology, and urban history, and a key guide for future scholarship.

Over 40 developing countries annually report death statistics to the World Health Organization or the United Nations Statistical Office, yet their utility for measuring levels and trends in mortality, particularly among adults, remains uncertain due to a lack of confidence in the completeness of death registration. Death distribution methods have been widely applied to estimate the completeness of death registration and correct for incompleteness. However, these methods have not been extensively validated in real populations in the presence of measurement error. In this paper, we use simulated populations where we know the true level of death registration completeness to characterize the performance of the three main methods in wide use for assessing the completeness of death registration: synthetic extinct generations, generalized growth balance and a hybrid of the two.