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141.
Elizabeth Dhuey David Figlio Krzysztof Karbownik Jeffrey Roth 《Journal of policy analysis and management》2019,38(3):538-578
We present evidence of a positive relationship between school starting age and children's cognitive development from ages 6 to 18 using a fuzzy regression discontinuity design and large‐scale population‐level birth and school data from the state of Florida. We estimate effects of being old for grade (being born in September vs. August) that are remarkably stable—always around 0.2 SD difference in test scores—across a wide range of heterogeneous groups, based on maternal education, poverty at birth, race/ethnicity, birth weight, gestational age, and school quality. While the September‐August difference in kindergarten readiness is dramatically different by subgroup, by the time students take their first exams, the heterogeneity in estimated effects on test scores effectively disappears. We do, however, find significant heterogeneity in other outcome measures such as disability status and middle and high school course selections. We also document substantial variation in compensatory behaviors targeted towards young‐for‐grade children. While the more affluent families tend to redshirt their children, young‐for‐grade children from less affluent families are more likely to be retained in grades prior to testing. School district practices regarding retention and redshirting are correlated with improved outcomes for the groups less likely to use those remediation approaches (i.e., retention in the case of more affluent families and redshirting in the case of less affluent families.) Finally, we find that very few school policies or practices mitigate the test score advantage of September‐born children. 相似文献
142.
Inequality in both income and wealth has grown rapidly in the United States since the 1970s. Over the same period, homeownership rates increased in step with expansionist government policies and the development of subprime and other exotic loan products, and housing affordability challenges emerged as the most prevalent housing problem for owners and renters alike. The subprime lending and foreclosure crises of the 2000s stretched households financially, threatening the traditional economic benefits of homeownership, bringing into stark relief the ways in which housing and inequality mutually influence one another, and implicating homeownership, housing affordability, and subprime lending in the widening gap between the rich and the poor. This article examines the changing roles of homeownership, housing affordability, and subprime lending in contemporary U.S. inequality by, first, describing trends in county inequality and housing characteristics and, second, modeling inequality as a function of the previous decade's housing characteristics over the period of 1980–2010. We build upon past models of county inequality by more explicitly considering causal order, place characteristics, and state and regional fixed effects. The results confirm that homeownership, affordability, and subprime lending not only reflect existing inequalities but also perpetuate those inequalities over time. Homeownership promotes equality, affordability problems undermine it, and subprime lending has the potential to ameliorate inequality in certain contexts, but these effects shift significantly over time, particularly as a result of widespread foreclosures and economic recession. Our analysis establishes the importance of housing in explaining contemporary inequality, highlights how place characteristics and causal ordering may improve county inequality models, and provides a foundation for future studies examining inequality in light of the Great Recession and the foreclosure crisis. 相似文献
143.
States producing gas and oil have long levied severance taxes at the point of extraction, commonly placing most revenues into general funds. These taxes have assumed new meaning in many states amid the expansion of gas and oil production accompanying the advent of hydraulic fracturing. We reviewed all major statutes and constitutional amendments related to severance taxes that were enacted at the state level during the first decade of the “shale era” (2005–14). There have been only modest adjustments in statutory tax rates and some evidence that states have attempted to reduce these rates, possibly in response to growing national production. In turn, there is also evidence that states have begun to pursue more targeted strategies for revenue use, including some expanded focus on responding to the negative externalities linked to drilling, expanded revenue sharing with localities, and increased long‐term protection of resources through state trust funds. 相似文献
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Election forecasting has experienced considerable growth as a subfield within political science. Research work on United Kingdom elections has been cutting edge here. The recent 2010 general election afforded the opportunity for a trial of different forecasting methodologies. These efforts are showcased in this volume, and include standard, and not-so-standard, statistical models. Overall, these models perform well, foreseeing the unprecedented outcome of a “hung parliament”, as most pollsters and pundits did not. Moreover, they achieved this accuracy with forecasts well in advance of the election itself. 相似文献
146.
To address the challenge of capturing latent fingerprint evidence from metal surfaces, a new method of latent fingerprint enhancement based on electrochromic polymer films has recently been developed. Here, we present a study comparing the development and visualization of nonvisible fingerprints on stainless steel substrates using this electrochromic enhancement approach with three classical methods (dusting, wet powder, and cyanoacrylate fuming). Two variants of the electrochromic enhancement method were utilized with polyaniline and poly(3,4-ethylenedioxythiophene) as the electrochromic materials. Fingerprint samples were taken from different donors (varying in age and gender) and were exposed to different environments for systematically varied periods of time (up to 28 days). The environments represent plausible evidential scenarios: left under ambient conditions, washed with aqueous soap solution, washed with acetone, submerged in water, and maintained at elevated temperature. The electrochromic enhancement procedure frequently outperformed the traditional methods, particularly for samples exposed to more challenging histories. 相似文献
147.
Bolton-King RS Bencsik M Evans JP Smith CL Allsop DF Painter JD Cranton WM 《Forensic science international》2012,220(1-3):197-209
This paper demonstrates a numerical pattern recognition method applied to curvilinear image structures. These structures are extracted from physical cross-sections of cast internal pistol barrel surfaces. Variations in structure arise from gun design and manufacturing method providing a basis for discrimination and identification. Binarised curvilinear land transition images are processed with fast Fourier transform on which principal component analysis is performed. One-way analysis of variance (95% confidence interval) concludes significant differentiation between 11 barrel manufacturers when calculating weighted Euclidean distance between any trio of land transitions and an average land transition for each barrel in the database. The proposed methodology is therefore a promising novel approach for the classification and identification of firearms. 相似文献
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