DOES AFFIRMATIVE ACTION AFFECT PRODUCTIVITY IN THE INDIAN RAILWAYS?

Our objective in this paper is to shed some empirical light on a claim often made by critics of affirmative action policies: that increasing the representation of members of marginalized communities in jobs – and especially in relatively skilled positions – comes at a cost of reduced efficiency. We undertake a systematic empirical analysis of productivity in the Indian Railways in order to determine whether increasing proportions of Scheduled Castes and Scheduled Tribes in railway employment – largely a consequence of India's affirmative action policies – have actually reduced productive efficiency in the railway system. We find no evidence that higher percentages of Scheduled Castes and Scheduled Tribes in the railway labour force have reduced productivity. Indeed, some of our results suggest that the opposite is true, providing tentative support for the claim that greater labour force diversity boosts productivity.affirmative action; labour force; productivity; Indian railways

Heart and Minds: A Social Model of U.S. Productivity Growth

macroeconomics, product growth

"Economics in Context: The Need for a New Textbook"

economics education, textbooks, economic theory

Characterization of the optical and X-ray properties of the northwestern wisps in the Crab Nebula

We have studied the wisps to the north-west of the Crab pulsar as part of a multi-wavelength campaign in the visible and in X-rays. Optical observations were obtained using the Nordic Optical Telescope in La Palma and X-ray observations were made with the Chandra X-ray Observatory. The observing campaign took place from 2010 October until 2012 September. About once per year we observe wisps forming and peeling off from (or near) the region commonly associated with the termination shock of the pulsar wind. We find that the exact locations of the northwestern wisps in the optical and in X-rays are similar but not coincident, with X-ray wisps preferentially located closer to the pulsar. This suggests that the optical and X-ray wisps are not produced by the same particle distribution. Our measurements and their implications are interpreted in terms of a Doppler-boosted ring model that has its origin in magne- tohydrodynamic (MHD) modelling. While the Doppler boosting factors inferred from the X-ray wisps are consistent with current MHD simulations of pulsar wind nebulae (PWN), the optical boosting factors are not, and typically exceed values from MHD simulations by about a factor of 3.Comment: 11 pages, 12 figure

The relevance of the Chinese experience for third world economic development

If the ten elements of Chinese development strategy discussed earlier are to provide object lessons relevant for other third world nations, they must be potentially transferable to other societies. The extent to which each element of the strategy is transferable depends on the conditions under which it can be successfully implemented, and on the degree to which these conditions are satisfied in other third world nations. I had also sought to determine what political-economic, geographical, and historical conditions are required for the successful implementation of each of the ten elements of strategy. The results of this analysis are summarized in the form of a matrix in Table 1. Each of the ten elements of strategy under discussion requires at least one - and often many more - of the major features of China's political-economic system. In all cases an effective and extensive system of public administration and/or a massoriented class structure are required, and in most cases a considerable degree of public ownership of the means of production and administrative control of resource allocation is either necessary or helpful. Less often required, but crucial in a few cases, are a central government with the power to mobilize resources on a large scale, a political leadership capable of influencing and involving people on a wide scale, and a ruraloriented class structure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43659/1/11186_2004_Article_BF00207280.pd

Exposure to Polyfluoroalkyl Chemicals and Attention Deficit/Hyperactivity Disorder in U.S. Children 12–15 Years of Age

Background: Polyfluoroalkyl chemicals (PFCs) have been widely used in consumer products. Exposures in the United States and in world populations are widespread. PFC exposures have been linked to various health impacts, and data in animals suggest that PFCs may be potential developmental neurotoxicants. Objectives: We evaluated the associations between exposures to four PFCs and parental report of diagnosis of attention deficit/hyperactivity disorder (ADHD). Methods: Data were obtained from the National Health and Nutrition Examination Survey (NHANES) 1999–2000 and 2003–2004 for children 12–15 years of age. Parental report of a previous diagnosis by a doctor or health care professional of ADHD in the child was the primary outcome measure. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) levels were measured in serum samples from each child. Results: Parents reported that 48 of 571 children included in the analysis had been diagnosed with ADHD. The adjusted odds ratio (OR) for parentally reported ADHD in association with a 1-μg/L increase in serum PFOS (modeled as a continuous predictor) was 1.03 [95% confidence interval (CI), 1.01–1.05]. Adjusted ORs for 1-μg/L increases in PFOA and PFHxS were also statistically significant (PFOA: OR = 1.12; 95% CI, 1.01–1.23; PFHxS: OR = 1.06; 95% CI, 1.02–1.11), and we observed a nonsignificant positive association with PFNA (OR = 1.32; 95% CI, 0.86–2.02). Conclusions: Our results, using cross-sectional data, are consistent with increased odds of ADHD in children with higher serum PFC levels. Given the extremely prevalent exposure to PFCs, follow-up of these data with cohort studies is needed

Limited resilience of the soil microbiome to mechanical compaction within four growing seasons of agricultural management

Soil compaction affects many soil functions, but we have little information on the resistance and resilience of soil microorganisms to this disturbance. Here, we present data on the response of soil microbial diversity to a single compaction event and its temporal evolution under different agricultural management systems during four growing seasons. Crop yield was reduced (up to −90%) in the first two seasons after compaction, but mostly recovered in subsequent seasons. Soil compaction increased soil bulk density (+15%), and decreased air permeability (−94%) and gas diffusion (−59%), and those properties did not fully recover within four growing seasons. Soil compaction induced cropping system-dependent shifts in microbial community structures with little resilience over the four growing seasons. Microbial taxa sensitive to soil compaction were detected in all major phyla. Overall, anaerobic prokaryotes and saprotrophic fungi increased in compacted soils, whereas aerobic prokaryotes and plant-associated fungi were mostly negatively affected. Most measured properties showed large spatial variability across the replicated blocks, demonstrating the dependence of compaction effects on initial conditions. This study demonstrates that soil compaction is a disturbance that can have long-lasting effects on soil properties and soil microorganisms, but those effects are not necessarily aligned with changes in crop yield

Chiral Extrapolation: An Analogy with Effective Field Theory

We draw an analogy between the chiral extrapolation of lattice QCD calculations from large to small quark masses and the interpolation between the large mass (weak field) and small mass (strong field) limits of the Euler--Heisenberg QED effective action. In the latter case, where the exact answer is known, a simple extrapolation of a form analogous to those proposed for the QCD applications is shown to be surprisingly accurate over the entire parameter range.Comment: 6 pp, revtex, 3 figs; minor changes -- version to appear in PL

Theories of American Imperialism: A Critical Evaluation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68828/2/10.1177_048661347400600303.pd