S. L. Morgan

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Least squares regression estimates of causal effects are conditional-variance-weighted estimates of individual-level causal effects. In this paper, we extract from the literature on counterfactual causality a simple nine-step routine to determine whether or not the implicit weighting of regression has generated a misleading estimate of the average causal(More)
The unreliability of multivariate outlier detection techniques such as Mahalanobis distance and hat matrix leverage has been known in the statistical community for well over a decade. However, only within the past few years has a serious effort been made to introduce robust methods for the detection of multivariate outliers into the chemical literature.(More)
In this article, we analyze gender differences in college major selection for respondents to the Education Longitudinal Study (2002-2006), focusing on educational pathways through college that lead to science, engineering, or doctoral-track medicine occupations and to non-doctoral track clinical and health sciences occupations. We show that gender(More)
Daniel J. Benjamin, James O. Berger, Magnus Johannesson, Brian A. Nosek, E.-J. Wagenmakers, Richard Berk, Kenneth A. Bollen, Björn Brembs, Lawrence Brown, Colin Camerer, David Cesarini, Christopher D. Chambers, Merlise Clyde, Thomas D. Cook, Paul De Boeck, Zoltan Dienes, Anna Dreber, Kenny Easwaran, Charles Efferson, Ernst Fehr, Fiona Fidler, Andy P. Field,(More)
Essential to forensic laboratories is the desire to find a more sensitive, rapid method of analyzing Delta9-tetrahydrocannabinol (THC) and metabolite in biological specimens. Disposable pipette extraction (DPX) is a valuable method in extracting THC and 11-nor-Delta9-tetrahydrocannabinol-9-carboxylic acid (THCc) in blood and THCc in urine. Less waste and(More)
A multivariate kinetic model of aqueous fipronil photodegradation was developed as a function of dissolved organic matter (DOM), bicarbonate, and nitrate at concentrations that bracketthose commonly observed in natural waters (ca. 0-10 mg/L). Several pathways were available for fipronil photodegradation in this system, including direct photolysis and(More)
The methodology of causal analysis in the social sciences is often divided into two ideal type research scenarios: experimental social science and observational social science. For experimental social science, the researcher can manipulate the cause of interest. The most common research design is one where the analyst assigns values of the cause according(More)
When progress in applied research slows because opposing coalitions of investigators privilege their favored models, methodologists can contribute by addressing a tractable unresolved question that is relevant to all competing positions. In this article, the literature on educational attainment is addressed, broadly by focusing on alternative positions on(More)
The ability of Raman microspectroscopy to distinguish between rutile and anatase forms of the inorganic pigment titanium dioxide (TiO(2)) and to make quantitative measurements of titania loading in fibers is demonstrated. Issues that affect the validity of the Raman measurements include the spatial heterogeneity of TiO(2) in the fiber, the polarization of(More)