507 research outputs found
A Statistical Look at Roger Clemensâ Pitching Career
A recent report (Hendricks Sports Management, LP, et al, 2008) issued by Hendricks Sports Management, LP, claims to provide evidence for the lack of use of performance-enhancing substances (PESs) by Hall-of-Fame caliber pitcher Roger Clemens, a claim based on an analysis of his career statistics (using ERA = earned run average, K rate = strikeout rate, innings pitched), both in isolation and in comparison to other power pitchers of his era (Randy Johnson, Nolan Ryan, and Curt Schilling).
In this research, we re-examine Roger Clemensâ career using a more complete and stable set of pitching measures (WHIP = walks + hits per inning pitched, BAA = batting average against, ERA, BB rate = rate of walks per batter faced, K rate), and by using a broader (census) comparison set of pitchers with similar longevity in order to reduce the selection bias inherent in the Hendricks report. In contrast to Hendricksâ report, our analysis examines not only late career performance but also early- and mid-career trends. Our findings can be summarized as follows:
Using simple quadratic functions, and an occasional spline to relate the above pitching measures to age, we demonstrate a number of empirical regularities: Roger Clemensâ career is atypical with respect to his peer group. While most pitchers with comparable longevity improve for the first half of their career, peaking just past the age of 30 and then declining (an inverted-U shape), Roger Clemensâ career statistics shows a decrease into his early thirties followed by a marked improvement late in his career (more of a U-shape). This pattern is consistent across most measures for Roger Clemens, yet for certain measures is not unique to him. That is, other pitchers have atypical patterns as well for some, but not all other tested measures.
Our analyses suggest what we, as statisticians, have postulated all along: empirical association is not causation, and neither the Hendricks report nor ours can prove or disprove the use of PESs by any given player. This is because players are indeed unique, and due to the short-time series and sparseness of comparable players there is low power to assess specific hypotheses. However, our analyses clearly suggest that Roger Clemensâ career pitching trajectory is atypical
A randomised controlled trial (MindChamp) of a mindfulness-based intervention for children with ADHD and their parents
A randomised controlled trial (MindChamp) of a mindfulness-based intervention for children with ADHD and their parents
BACKGROUND: Family mindfulnessâbased intervention (MBI) for child attentionâdeficit/hyperactivity disorder (ADHD) targets child selfâcontrol, parenting and parental mental health, but its effectiveness is still unclear. METHODS: MindChamp is a preâregistered randomised controlled trial comparing an 8âweek family MBI (called âMYmindâ) in addition to careâasâusual (CAU) (nâ=â55) with CAUâonly (nâ=â48). Children aged 8â16âyears with remaining ADHD symptoms after CAU were enrolled together with a parent. Primary outcome was postâtreatment parentârated child selfâcontrol deficits (BRIEF); post hoc, Reliable Change Indexes were explored. Secondary child outcomes included ADHD symptoms (parent/teacherârated Connersâ and SWAN; teacherârated BRIEF), other psychological symptoms (parent/teacherârated), wellâbeing (parentârated) and mindfulness (selfârated). Secondary parent outcomes included selfâratings of ADHD symptoms, other psychological symptoms, wellâbeing, selfâcompassion and mindful parenting. Assessments were conducted at postâtreatment, 2â and 6âmonth followâup. RESULTS: Relative to CAUâonly, MBI+CAU resulted in a small, statistically nonâsignificant postâtreatment improvement on the BRIEF (intentionâtoâtreat: dâ=â0.27, pâ=â.18; per protocol: dâ=â0.33, pâ=â.11). Significantly more children showed reliable postâtreatment improvement following MBI+CAU versus CAUâonly (32% versus 11%, pâ<â.05, NumberâNeededâtoâTreatâ=â4.7). ADHD symptoms significantly reduced postâtreatment according to parent (Connersâ and SWAN) and teacher ratings (BRIEF) per protocol. Only parentârated hyperactivity impulsivity (SWAN) remained significantly reduced at 6âmonth followâup. Postâtreatment group differences on other secondary child outcomes were consistently favour of MBI+CAU, but mostly nonâsignificant; no significant differences were found at followâups. Regarding parent outcomes, significant postâtreatment improvements were found for their own ADHD symptoms, wellâbeing and mindful parenting. At followâups, some significant effects remained (ADHD symptoms, mindful parenting), some additional significant effects appeared (other psychological symptoms, selfâcompassion) and others disappeared/remained nonâsignificant. CONCLUSIONS: Family MBI+CAU did not outperform CAUâonly in reducing child selfâcontrol deficits on a group level but more children reliably improved. Effects on parents were larger and more durable. When CAU for ADHD is insufficient, family MBI could be a valuable addition
Magnetic structure of CeRhIn under magnetic field
The magnetically ordered ground state of CeRhIn at ambient pressure and
zero magnetic field is an incomensurate helicoidal phase with the propagation
vector =(1/2, 1/2, 0.298) and the magnetic moment in the basal plane of
the tetragonal structure. We determined by neutron diffraction the two
different magnetically ordered phases of CeRhIn evidenced by bulk
measurements under applied magnetic field in its basal plane. The low
temperature high magnetic phase corresponds to a sine-wave structure of the
magnetization being commensurate with =(1/2, 1/2, 1/4). At high
temperature, the phase is incommensurate with =(1/2, 1/2, 0.298) and a
possible small ellipticity. The propagation vector of this phase is the same as
the one of the zero-field structure.Comment: 4 Figure
Deviations from normative brain white and gray matter structure are associated with psychopathology in youth
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National interest to global reform: patterns of reasoning in British foreign policy discourse
Discussion of the national interest often focuses on how Britain's influence can be maximized, rather than on the goals that influence serves. Yet what gives content to claims about the national interest is the means-ends reasoning which links interests to deeper goals. In ideal-typical terms, this can take two forms. The first, and more common, approach is conservative: it infers national interests and the goals they advance from existing policies and commitments. The second is reformist: it starts by specifying national goals and then asks how they are best advanced under particular conditions. New Labour's foreign policy discourse is notable for its explicit use of a reformist approach. Indeed, Gordon Brown's vision of a 'new global society' not only identifies global reform as a key means of fulfilling national goals, but also thereby extends the concept of the national interest well beyond a narrow concern with national security
The political economy of the disability insurance: theory and evidence of gubernatorial learning
Abstract
The dramatic rise in the disability insurance (DI) rolls in the last 20 years has been the subject of much controversy. While the relationship between DI and labor force participation has been the subject of a growing literature, the mechanism of this transition from employment to DI remains unclear. We hypothesize that one mechanism is the state-level administration of the program which creates a classic principal-agent problem. We analyze the conflict of interests for Disability Determination Services agencies between Social Security Administration (SSA) standards and state gubernatorial political interests interacted with the increased demand for disability insurance as an alternative for low-skilled employment during the period of 1982 to 2013. We find evidence that multi-term governors allow a greater fraction of applicants than do first-term governors, but only up to year 2000, when allowance rates started to decrease over time. We develop a model that illustrates how these differences can be due to the type of monitoring conducted by the SSA. We provide additional evidence supporting this hypothesis analyzing how the effects interact with economic and political constraints.
JEL codes
H55, I18, I38, G22</jats:p
An Experiment on Prediction Markets in Science
Prediction markets are powerful forecasting tools. They have the potential to aggregate private information, to generate and disseminate a consensus among the market participants, and to provide incentives for information acquisition. These market functionalities can be very valuable for scientific research. Here, we report an experiment that examines the compatibility of prediction markets with the current practice of scientific publication. We investigated three settings. In the first setting, different pieces of information were disclosed to the public during the experiment. In the second setting, participants received private information. In the third setting, each piece of information was private at first, but was subsequently disclosed to the public. An automated, subsidizing market maker provided additional incentives for trading and mitigated liquidity problems. We find that the third setting combines the advantages of the first and second settings. Market performance was as good as in the setting with public information, and better than in the setting with private information. In contrast to the first setting, participants could benefit from information advantages. Thus the publication of information does not detract from the functionality of prediction markets. We conclude that for integrating prediction markets into the practice of scientific research it is of advantage to use subsidizing market makers, and to keep markets aligned with current publication practice
The Unintended Consequences of a European Neighbourhood Policy without Russia
After Russiaâs retreat from the European Neighbourhood Policy, the EUâs policy towards its eastern neighbours was split up. The internal unintended consequence of the EUâs choice to leave its policy unaltered was a tension between the objective of privileged relations with ENP countries and a promise to recognise the interests of Russia as an equal partner. Externally, the unintended outcome was that this fostered two opposing strategic environments: a cooperative one for the EaP and a competitive one with Russia. In terms of the management of unintended consequences, the EU has actively sought to reinforce its normative hegemony towards EaP countries, while at the same time mitigating certain negative unintended effects
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