21 research outputs found
Maternal Smoking, Misclassification, and Infant Health
Identifying the causal effect of prenatal maternal smoking on infant health is complicated by unobservable maternal characteristics and behaviors which are plausibly related to both birth outcomes and a mother’s propensity to smoke. Previous studies have addressed the omitted variables problem using instrumental variables (IV) techniques. However, with self-reported data on maternal smoking, misreporting can induce more severe biases in IV estimates than in OLS. This paper proposes an approach based on parametric methods for misclassified binary dependent variables that simultaneously addresses the endogeneity and measurement error problems. The relationship between infant health and maternal smoking is then re-examined using US Birth Records. I find that roughly 30% of smoking mothers are misclassified as non-smokers. As a result, conventional IV estimates deliver implausibly large birth weight losses (upwards of 1,000 grams among African Americans). Accounting for misclassification yields estimates that are considerably smaller in magnitude and more consistent with experimental evidence.Misclassification, prenatal maternal smoking, birth outcomes
Maternal Smoking, Misclassification, and Infant Health
Identifying the causal effect of prenatal maternal smoking on infant health is complicated by unobservable maternal characteristics and behaviors which are plausibly related to both birth outcomes and a mother’s propensity to smoke. Previous studies have addressed the omitted variables problem using instrumental variables (IV) techniques. However, with self-reported data on maternal smoking, misreporting can induce more severe biases in IV estimates than in OLS. This paper proposes an approach based on parametric methods for misclassified binary dependent variables that simultaneously addresses the endogeneity and measurement error problems. The relationship between infant health and maternal smoking is then re-examined using US Birth Records. I find that roughly 30% of smoking mothers are misclassified as non-smokers. As a result, conventional IV estimates deliver implausibly large birth weight losses (upwards of 1,000 grams among African Americans). Accounting for misclassification yields estimates that are considerably smaller in magnitude and more consistent with experimental evidence
Maternal Smoking, Misclassification, and Infant Health
Identifying the causal effect of prenatal maternal smoking on infant health is complicated by unobservable maternal characteristics and behaviors which are plausibly related to both birth outcomes and a mother’s propensity to smoke. Previous studies have addressed the omitted variables problem using instrumental variables (IV) techniques. However, with self-reported data on maternal smoking, misreporting can induce more severe biases in IV estimates than in OLS. This paper proposes an approach based on parametric methods for misclassified binary dependent variables that simultaneously addresses the endogeneity and measurement error problems. The relationship between infant health and maternal smoking is then re-examined using US Birth Records. I find that roughly 30% of smoking mothers are misclassified as non-smokers. As a result, conventional IV estimates deliver implausibly large birth weight losses (upwards of 1,000 grams among African Americans). Accounting for misclassification yields estimates that are considerably smaller in magnitude and more consistent with experimental evidence
The Effect of Shift Structure on Performance
The effect of shift structure on worker performance and productivity is of increasing interest to firms and regulatory bodies. Using approximately 743,000 emergency medical incidents attended by 2,381 paramedics in Mississippi, we evaluate the extent that paramedics\u27 performance toward the end of shifts is impacted by shift length. We find evidence that performance deteriorates toward the end of long shifts, and argue that fatigue is the mediating factor. Our calculations imply that such deterioration may result in a 0.76 percent increase in 30-day mortality. These findings have implications for workforce organization, calling attention to regulation designed to limit extended work hours
The Effect of Shift Structure on Performance: The Role of Fatigue for Paramedics
The effect of shift structure on worker performance and productivity is an issue of increasing interest to firms and regulatory bodies. Using approximately 742,000 emergency medical incidents attended by 2,400 paramedics in the state of Mississippi, we evaluate the extent to which paramedics’ performance towards the end of their shift is impacted by its length. We find evidence that their performance deteriorates towards the end of long shifts, and argue that fatigue is the mediating factor. These findings have implications for workforce organization, calling attention to regulation designed to limit extended work hours.
On the Determinants of Organizational Forgetting
Studies of organizational learning and forgetting identify potential channels through which the firm’s production experience is lost. While the ability to distinguish between these channels has implications for efficient resource allocation within the firm, to date, their relative importance has been ignored. This paper develops a framework for eliciting the contributions of labor turnover and human capital depreciation to organizational forgetting. We apply our framework to a novel dataset of ambulance companies and their workforce. We find evidence of organizational forgetting, which results from sizable skill decay and turnover effects, with the latter having twice the magnitude of the former
On the Determinants of Organizational Forgetting
Studies of organizational learning and forgetting identify potential channels through which the firm’s production experience is lost. While the ability to distinguish between these channels has implications for efficient resource allocation within the firm, to date, their relative importance has been ignored. This paper develops a framework for eliciting the contributions of labor turnover and human capital depreciation to organizational forgetting. We apply our framework to a novel dataset of ambulance companies and their workforce. We find evidence of organizational forgetting, which results from sizable skill decay and turnover effects, with the latter having twice the magnitude of the former
The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase
The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray
spectrometer, studied since 2015 for flying in the mid-30s on the Athena space
X-ray Observatory, a versatile observatory designed to address the Hot and
Energetic Universe science theme, selected in November 2013 by the Survey
Science Committee. Based on a large format array of Transition Edge Sensors
(TES), it aims to provide spatially resolved X-ray spectroscopy, with a
spectral resolution of 2.5 eV (up to 7 keV) over an hexagonal field of view of
5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement
Review (SRR) in June 2022, at about the same time when ESA called for an
overall X-IFU redesign (including the X-IFU cryostat and the cooling chain),
due to an unanticipated cost overrun of Athena. In this paper, after
illustrating the breakthrough capabilities of the X-IFU, we describe the
instrument as presented at its SRR, browsing through all the subsystems and
associated requirements. We then show the instrument budgets, with a particular
emphasis on the anticipated budgets of some of its key performance parameters.
Finally we briefly discuss on the ongoing key technology demonstration
activities, the calibration and the activities foreseen in the X-IFU Instrument
Science Center, and touch on communication and outreach activities, the
consortium organisation, and finally on the life cycle assessment of X-IFU
aiming at minimising the environmental footprint, associated with the
development of the instrument. Thanks to the studies conducted so far on X-IFU,
it is expected that along the design-to-cost exercise requested by ESA, the
X-IFU will maintain flagship capabilities in spatially resolved high resolution
X-ray spectroscopy, enabling most of the original X-IFU related scientific
objectives of the Athena mission to be retained. (abridged).Comment: 48 pages, 29 figures, Accepted for publication in Experimental
Astronomy with minor editin
The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase
The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory. Athena is a versatile observatory designed to address the Hot and Energetic Universe science theme, as selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), X-IFU aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over a hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR (i.e. in the course of its preliminary definition phase, so-called B1), browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters, such as the instrument efficiency, spectral resolution, energy scale knowledge, count rate capability, non X-ray background and target of opportunity efficiency. Finally, we briefly discuss the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, touch on communication and outreach activities, the consortium organisation and the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. The X-IFU will be provided by an international consortium led by France, The Netherlands and Italy, with ESA member state contributions from Belgium, Czech Republic, Finland, Germany, Poland, Spain, Switzerland, with additional contributions from the United States and Japan.The French contribution to X-IFU is funded by CNES, CNRS and CEA. This work has been also supported by ASI (Italian Space Agency) through the Contract 2019-27-HH.0, and by the ESA (European Space Agency) Core Technology Program (CTP) Contract No. 4000114932/15/NL/BW and the AREMBES - ESA CTP No.4000116655/16/NL/BW. This publication is part of grant RTI2018-096686-B-C21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. This publication is part of grant RTI2018-096686-B-C21 and PID2020-115325GB-C31 funded by MCIN/AEI/10.13039/501100011033
On the Determinants of Organizational Forgetting
Studies of organizational learning and forgetting identify potential channels through which the firm's production experience is lost. These channels have differing implications for efficient resource allocation within the firm, but their relative importance has been ignored to date. We develop a framework for distinguishing the contributions of labor turnover and human capital depreciation to organizational forgetting. We apply our framework to a novel dataset of ambulance companies and their workforce. We find evidence of organizational forgetting, which results from skill decay and turnover effects. The latter has twice the magnitude of the former. (JEL D23, D83, J24, J63)