The Government's Impact on the Labor Market Status of Black Americans: A Critical Review

This paper surveys recent evidence on the impact of government programs on the measured labor market status of black Americans. In this paper, we argue that previous studies neglect the impact of recent government policy on the supply side of the labor market, and that the supply side effects of recent policy play an important role in explaining the recent measured increase in the ratio of the wages and incomes of blacks to the wages and incomes of whites.

Reassessment of the evidence for postcranial skeletal pneumaticity in Triassic archosaurs, and the early evolution of the avian respiratory system.

Uniquely among extant vertebrates, birds possess complex respiratory systems characterised by the combination of small, rigid lungs, extensive pulmonary air sacs that possess diverticula that invade (pneumatise) the postcranial skeleton, unidirectional ventilation of the lungs, and efficient crosscurrent gas exchange. Crocodilians, the only other living archosaurs, also possess unidirectional lung ventilation, but lack true air sacs and postcranial skeletal pneumaticity (PSP). PSP can be used to infer the presence of avian-like pulmonary air sacs in several extinct archosaur clades (non-avian theropod dinosaurs, sauropod dinosaurs and pterosaurs). However, the evolution of respiratory systems in other archosaurs, especially in the lineage leading to crocodilians, is poorly documented. Here, we use µCT-scanning to investigate the vertebral anatomy of Triassic archosaur taxa, from both the avian and crocodilian lineages as well as non-archosaurian diapsid outgroups. Our results confirm previous suggestions that unambiguous evidence of PSP (presence of internal pneumatic cavities linked to the exterior by foramina) is found only in bird-line (ornithodiran) archosaurs. We propose that pulmonary air sacs were present in the common ancestor of Ornithodira and may have been subsequently lost or reduced in some members of the clade (notably in ornithischian dinosaurs). The development of these avian-like respiratory features might have been linked to inferred increases in activity levels among ornithodirans. By contrast, no crocodile-line archosaur (pseudosuchian) exhibits evidence for unambiguous PSP, but many of these taxa possess the complex array of vertebral laminae and fossae that always accompany the presence of air sacs in ornithodirans. These laminae and fossae are likely homologous with those in ornithodirans, which suggests the need for further investigation of the hypothesis that a reduced, or non-invasive, system of pulmonary air sacs may be have been present in these taxa (and secondarily lost in extant crocodilians) and was potentially primitive for Archosauria as a whole

Levels and long-term trends in earnings inequality: Overcoming Current Population Survey censoring problems using the GB2 distribution

Over its history, the March Current Population Survey (CPS) has increasingly captured the upper tail of the distribution of all sources of income. This, together with time-consistency problems in top coding, means that users of both the public-use and restricted-access CPS will understate the level of wage earnings and income inequality in earlier years and overstate their growth over time. We address this problem by modeling the personal earnings of full-time, full-year workers using the generalized beta distribution of the second kind, calculating Gini coefficients from the estimated parameters, and comparing them with past findings

Libel and the First Amendment: \u3ci\u3eTime, Inc. v. Firestone\u3c/i\u3e, 424 U.S. 448 (1976)

I. Introduction II. History III. The Issues … A. Public Figure … 1. Prominence or Participation in Controversy … 2. Selective Application of Gertz … 3. What Community? … 4. Divorce Proceedings … 5. Public Figure Rationale … B. Reports of Judicial Proceedings .. C. Actual Injury … D. Fault IV. Conclusio

The Early Evolution of Rhynchosaurs

The rhynchosaurian archosauromorphs are an important and diverse group of fossil tetrapods that first appeared during the Early Triassic and probably became extinct during the early Late Triassic (early Norian). Here, the early evolution of rhynchosaurs during the Early and early Middle Triassic (Induan-Anisian: 252.2-242 Mya) is reviewed based on new anatomical observations and their implications for the taxonomy, phylogenetic relationships and macroevolutionary history of the group. A quantitative phylogenetic analysis recovered a paraphyletic genus Rhynchosaurus, with “Rhynchosaurus” brodiei more closely related to hyperodapedontines than to Rhynchosaurus articeps. Therefore, a new genus is erected, resulting in the new combination Langeronyx brodiei. A body size analysis found two independent increases in size in the evolutionary history of rhynchosaurs, one among stenaulorhynchines and the other in the hyperodapedontine lineage. Maximum likelihood fitting of phenotypic evolution models to body size data found ambiguous results, with body size evolution potentially interpreted as fitting either a non-directional Brownian motion model or a stasis model. A Dispersal-ExtinctionCladogenesis analysis reconstructed the areas that are now South Africa and Europe as the ancestral areas of Rhynchosauria and Rhynchosauridae, respectively. The reconstruction of dispersal events between geographic areas that are broadly separated paleolatitudinally implies that barriers to the dispersal of rhynchosaurs from either side of the paleo-Equator during the Middle Triassic were either absent or permeable.Fil: Ezcurra, Martin Daniel. University of Birmingham; Reino Unido. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Montefeltro, Felipe C.. University of Birmingham; Reino Unido. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Butler, Richard J.. University of Birmingham; Reino Unid

Human Resource Management and Safety: Technical Efficiency and Economic Incentives

The authors present analysis of the impact of various HRM practices on firms’ workers’ compensation costs; specifically, which practices lower firms’ workers’ compensation costs and whether the impact is the result of changes in technical efficiency or comes through induced changes in workers’ behavior.https://research.upjohn.org/up_press/1037/thumbnail.jp