A nonparametric analysis of the U.S. earnings distribution

This paper examines the change in the earnings distribution and in the earnings distribution conditional on years of schooling and experience for white male full-time, year-round workers in the United States from 1967 to 1992. Ginther uses nonparametric kernel estimators to examine changes in the unconditional and conditional earnings distributions and to estimate measures of conditional earnings inequality. Ginther compares estimates from parametric wage equations to nonparametric estimates and finds that parametric estimates are biased: earnings inequality did not change in equal proportions within cohorts and experience groups. Instead, inequality increased the most among workers with 10 and 12 years of schooling at all experience levels and among workers with both 16 years of schooling and less than 15 years experience. Inequality decreased among people with graduate levels of schooling. Controlled for levels of schooling and experience, real wages have declined drastically for all workers except those with more than 16 years of schooling or more than 25 years experience. Groups experiencing the largest increase in earnings inequality are also those with the largest decline in real wages.

Advancing biomedical science through investments in elite training

How can governments invest in the public good of science in a way that accelerates advancement and encourages innovation at the frontier of science–all the while acknowledging that investing in science means investing in scientists? The Ruth L. Kirschstein National Research Service Award (NRSA) program is a research-training program administered by the National Institutes of Health (NIH) that makes such investments. This study examines the impact of NRSA postdoctoral fellowships on subsequent career outcomes using NIH administrative records on applicants for the fellowship from 1996 to 2008. It finds that fellowships increased the probability of receiving subsequent research awards from 4.0 to 6.3 percentage points and of achieving a major independent research award from 2.6 to 4.6 percentage points. The findings demonstrate that federally funded fellowships promote the retention of scientists in the biomedical research workforce

Can Mentoring Help Female Assistant Professors? Interim Results from a Randomized Trial

While much has been written about the potential benefits of mentoring in academia, very little research documents its effectiveness. We present data from a randomized controlled trial of a mentoring program for female economists organized by the Committee for the Status of Women in the Economics Profession and sponsored by the National Science Foundation and the American Economics Association. To our knowledge, this is the first randomized trial of a mentoring program in academia. We evaluate the performance of three cohorts of participants and randomly-assigned controls from 2004, 2006, and 2008. This paper presents an interim assessment of the program’s effects. Our results suggest that mentoring works. After five years the 2004 treatment group averaged .4 more NSF or NIH grants and 3 additional publications, and were 25 percentage points more likely to have a top-tier publication. There are significant but smaller effects at three years post-treatment for the 2004 and 2006 cohorts combined. While it is too early to assess the ultimate effects of mentoring on the academic careers of program participants, the results suggest that this type of mentoring may be one way to help women advance in the Economics profession and, by extension, in other male-dominated academic fields.

Decoding Guilty Minds

A central tenet of Anglo-American penal law is that in order for an actor to be found criminally liable, a proscribed act must be accompanied by a guilty mind. While it is easy to understand the importance of this principle in theory, in practice it requires jurors and judges to decide what a person was thinking months or years earlier at the time of the alleged offense, either about the results of his conduct or about some elemental fact (such as whether the briefcase he is carrying contains drugs). Despite the central importance of this task in the administration of criminal justice, there has been very little research investigating how people go about making these decisions, and how these decisions relate to their intuitions about culpability. Understanding the cognitive mechanisms that govern this task is important for the law, not only to explore the possibility of systemic biases and errors in attributions of culpability but also to probe the intuitions that underlie them. In a set of six exploratory studies reported here, we examine the way in which individuals infer others’ legally relevant mental states about elemental facts, using the framework established over fifty years ago by the Model Penal Code (“MPC”). The widely adopted MPC framework delineates and defines the four now-familiar culpable mental states: purpose, knowledge, recklessness, and negligence. Our studies reveal that with little to no training, jury-eligible Americans can apply the MPC framework in a manner that is largely congruent with the basic assumptions of the MPC’s mental state hierarchy. However, our results also indicate that subjects’ intuitions about the level of culpability warranting criminal punishment diverge significantly from prevailing legal practice; subjects tend to regard recklessness as a sufficient basis for punishment under circumstances where the legislatures and courts tend to require knowledge

Parsing the Behavioral and Brain Mechanisms of Third-Party Punishment

The evolved capacity for third-party punishment is considered crucial to the emergence and maintenance of elaborate human social organization and is central to the modern provision of fairness and justice within society. Although it is well established that the mental state of the offender and the severity of the harm he caused are the two primary predictors of punishment decisions, the precise cognitive and brain mechanisms by which these distinct components are evaluated and integrated into a punishment decision are poorly understood. Using a brain-scanning technique known as functional magnetic resonance imaging (fMRI), we implemented a novel experimental design to functionally dissociate the mechanisms underlying evaluation, integration, and decision. This work revealed that multiple parts of the brain – some analytic, some subconscious or emotional – work in a systematic pattern to decide blameworthiness, assess harms, integrate those two decisions, and then ultimately select how a person should be punished. Specifically, harm and mental state evaluations are conducted in two different brain networks and then combined in the medial prefrontal and posterior cingulate areas of the brain, while the amygdala acts as a pivotal hub of the interaction between harm and mental state. This integrated information is then used by the right dorsolateral prefrontal cortex when the brain is making a decision on punishment amount. These findings provide a blueprint of the brain mechanisms by which neutral third parties make punishment decisions

Parsing the Behavioral and Brain Mechanisms of Third-Party Punishment.

UnlabelledThe evolved capacity for third-party punishment is considered crucial to the emergence and maintenance of elaborate human social organization and is central to the modern provision of fairness and justice within society. Although it is well established that the mental state of the offender and the severity of the harm he caused are the two primary predictors of punishment decisions, the precise cognitive and brain mechanisms by which these distinct components are evaluated and integrated into a punishment decision are poorly understood. Using fMRI, here we implement a novel experimental design to functionally dissociate the mechanisms underlying evaluation, integration, and decision that were conflated in previous studies of third-party punishment. Behaviorally, the punishment decision is primarily defined by a superadditive interaction between harm and mental state, with subjects weighing the interaction factor more than the single factors of harm and mental state. On a neural level, evaluation of harms engaged brain areas associated with affective and somatosensory processing, whereas mental state evaluation primarily recruited circuitry involved in mentalization. Harm and mental state evaluations are integrated in medial prefrontal and posterior cingulate structures, with the amygdala acting as a pivotal hub of the interaction between harm and mental state. This integrated information is used by the right dorsolateral prefrontal cortex at the time of the decision to assign an appropriate punishment through a distributed coding system. Together, these findings provide a blueprint of the brain mechanisms by which neutral third parties render punishment decisions.Significance statementPunishment undergirds large-scale cooperation and helps dispense criminal justice. Yet it is currently unknown precisely how people assess the mental states of offenders, evaluate the harms they caused, and integrate those two components into a single punishment decision. Using a new design, we isolated these three processes, identifying the distinct brain systems and activities that enable each. Additional findings suggest that the amygdala plays a crucial role in mediating the interaction of mental state and harm information, whereas the dorsolateral prefrontal cortex plays a crucial, final-stage role, both in integrating mental state and harm information and in selecting a suitable punishment amount. These findings deepen our understanding of how punishment decisions are made, which may someday help to improve them

Identification of Burkholderia pseudomallei Near-Neighbor Species in the Northern Territory of Australia

Identification and characterization of near-neighbor species are critical to the development of robust molecular diagnostic tools for biothreat agents. One such agent, Burkholderia pseudomallei, a soil bacterium and the causative agent of melioidosis, is lacking in this area because of its genomic diversity and widespread geographic distribution. The Burkholderia genus contains over 60 species and occupies a large range of environments including soil, plants, rhizospheres, water, animals and humans. The identification of novel species in new locations necessitates the need to identify the true global distribution of Burkholderia species, especially the members that are closely related to B. pseudomallei. In our current study, we used the Burkholderia-specific recA sequencing assay to analyze environmental samples from the Darwin region in the Northern Territory of Australia where melioidosis is endemic. Burkholderia recA PCR negative samples were further characterized using 16s rRNA sequencing for species identification. Phylogenetic analysis demonstrated that over 70% of the bacterial isolates were identified as B. ubonensis indicating that this species is common in the soil where B. pseudomallei is endemic. Bayesian phylogenetic analysis reveals many novel branches within the B. cepacia complex, one novel B. oklahomensis-like species, and one novel branch containing one isolate that is distinct from all other samples on the phylogenetic tree. During the analysis with recA sequencing, we discovered 2 single nucleotide polymorphisms in the reverse priming region of B. oklahomensis. A degenerate primer was developed and is proposed for future use. We conclude that the recA sequencing technique is an effective tool to classify Burkholderia and identify soil organisms in a melioidosis endemic area

Measurement of direct photon production at Tevatron fixed target energies

Measurements of the production of high transverse momentum direct photons by a 515 GeV/c piminus beam and 530 and 800 GeV/c proton beams in interactions with beryllium and hydrogen targets are presented. The data span the kinematic ranges of 3.5 < p_T < 12 GeV/c in transverse momentum and 1.5 units in rapidity. The inclusive direct-photon cross sections are compared with next-to-leading-order perturbative QCD calculations and expectations based on a phenomenological parton-k_T model.Comment: RevTeX4, 23 pages, 32 figures, submitted to Phys. Rev.

Cosmic ray tests of the D0 preshower detector

The D0 preshower detector consists of scintillator strips with embedded wavelength-shifting fibers, and a readout using Visible Light Photon Counters. The response to minimum ionizing particles has been tested with cosmic ray muons. We report results on the gain calibration and light-yield distributions. The spatial resolution is investigated taking into account the light sharing between strips, the effects of multiple scattering and various systematic uncertainties. The detection efficiency and noise contamination are also investigated.Comment: 27 pages, 24 figures, submitted to NIM