44,575 research outputs found

    Regularities and Irregularities in Order Flow Data

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    We identify and analyze statistical regularities and irregularities in the recent order flow of different NASDAQ stocks, focusing on the positions where orders are placed in the orderbook. This includes limit orders being placed outside of the spread, inside the spread and (effective) market orders. We find that limit order placement inside the spread is strongly determined by the dynamics of the spread size. Most orders, however, arrive outside of the spread. While for some stocks order placement on or next to the quotes is dominating, deeper price levels are more important for other stocks. As market orders are usually adjusted to the quote volume, the impact of market orders depends on the orderbook structure, which we find to be quite diverse among the analyzed stocks as a result of the way limit order placement takes place.Comment: 10 pages, 9 figure

    Inflation as a Strategic Response

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    In this paper, we examine the effect of increases in health care costs and general inflation on optimal insurance policies and waste in a model of imperfect information with costly auditing. We show that in such a setting, individuals will buy more than full insurance. Moreover, as the cost of medical increases, consumers (i.e., patients) reduce their probability of filing injustified claims, at the same time as insurance providers audit with lower probability. As a result, waste associated with costly auditing is reduced. We also show that a general increase in the opportunity cost of illness (reflected through lost wages due to illness) also decreases the likelihood of false claims, of auditing and thus of waste, but not as much as health care costs increase. Nous étudions dans ce document de recherche l'impact d'une augmentation des coûts des soins de santé et de l'inflation en général sur le contrat optimal d'assurance médicale et sur le gaspillage dans une économie où les agents-consommateurs possèdent une information privilégiée et où le principal-assureur doit encourir des coûts d'audit pour vérifier l'information des agents. Nous montrons dans cet article que les agents seront plus que pleinement assurés au sens où l'indemnité reçue est plus grande que la perte encourue. De plus, au fur et à mesure que le coût des soins de santé augmente, les agents réduisent leur probabilité de demander des soins de santé injustifiés, alors que le principal réduit sa probabilité d'audit. En conséquence, le gaspillage associé aux audits onéreux diminue. Nous montrons finalement qu'une augmentation dans le coût de la vie en général (que nous approximons par une augmentation des pertes de salaire encourues à cause de la maladie) réduit également le gaspillage associé aux audits,0501s dans une mesure moindre qu'une augmentation du coût des soins de santé.Health care fraud, asymmetric information, contract theory, Fraude médicale, information asymétrique, théorie des contrats

    Results of the 1986 NASA/FAA/DFVLR main rotor test entry in the German-Dutch wind tunnel (DNW)

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    An acoustics test of a 40%-scale MBB BO-105 helicopter main rotor was conducted in the Deutsch-Niederlandischer Windkanal (DNW). The research, directed by NASA Langley Research Center, concentrated on the generation and radiation of broadband noise and impulsive blade-vortex interaction (BVI) noise over ranges of pertinent rotor operational envelopes. Both the broadband and BVI experimental phases are reviewed, along with highlights of major technical results. For the broadband portion, significant advancement is the demonstration of the accuracy of prediction methods being developed for broadband self noise, due to boundary layer turbulence. Another key result is the discovery of rotor blade-wake interaction (BWI) as an important contributor to mid frequency noise. Also the DNW data are used to determine for full scale helicopters the relative importance of the different discrete and broadband noise sources. For the BVI test portion, a comprehensive data base documents the BVI impulsive noise character and directionality as functions of rotor flight conditions. The directional mapping of BVI noise emitted from the advancing side as well as the retreating side of the rotor constitutes a major advancement in the understanding of this dominant discrete mechanism

    Total factor productivity effects of interregional knowledge spillovers in manufacturing industries across Europe

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    The objective of this study is to identify knowledge spillovers that spread across regions in Europe and vary in magnitude for different industries. The study uses a panel of 203 NUTS-2 regions covering the 15 pre-2004 EU-member-states to estimate the impact over the period 1998-2003, and distinguish between five major industries. The study implements a fixed effects panel data regression model with spatial autocorrelation to estimate effects using patent applications as a measure of R&D output to capture the contribution of R&D (direct and spilled-over) to regional productivity at the industry level. The results suggest that interregional knowledge spillovers and their productivity effects are to a substantial degree geographically localised and this finding is consistent with the localisation hypothesis of knowledge spillovers. There is a substantial amount of heterogeneity across industries with evidence that two industries (electronics, and chemical industries) produce interregional knowledge spillovers that have positive and highly significant productivity effects. The study, moreover, confirms the importance of spatial autoregressive disturbance in the fixed effects model for measuring the TFP impact of interregional knowledge spillovers at the industry level.Total factor productivity, manufacturing industries, knowledge spillovers,patents, European regions, spatial econometrics

    Shadow epitaxy for in-situ growth of generic semiconductor/superconductor devices

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    Uniform, defect-free crystal interfaces and surfaces are crucial ingredients for realizing high-performance nanoscale devices. A pertinent example is that advances in gate-tunable and topological superconductivity using semiconductor/superconductor electronic devices are currently built on the hard proximity-induced superconducting gap obtained from epitaxial indium arsenide/aluminium heterostructures. Fabrication of devices requires selective etch processes; these exist only for InAs/Al hybrids, precluding the use of other, potentially superior material combinations. We present a crystal growth platform -- based on three-dimensional structuring of growth substrates -- which enables synthesis of semiconductor nanowire hybrids with in-situ patterned superconductor shells. This platform eliminates the need for etching, thereby enabling full freedom in choice of hybrid constituents. We realise and characterise all the most frequently used architectures in superconducting hybrid devices, finding increased yield and electrostatic stability compared to etched devices, along with evidence of ballistic superconductivity. In addition to aluminium, we present hybrid devices based on tantalum, niobium and vanadium. This is the submitted version of the manuscript. The accepted, peer reviewed version is available from Advanced Materials: http://doi.org/10.1002/adma.201908411 Previous title: Shadow lithography for in-situ growth of generic semiconductor/superconductor device

    Teaching Casual Random Blood Glucose Screening to Second-Year Dental Students

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    In our project, archived casual random blood glucose levels of second-year dental students who were taught the mechanics of self-testing were retrieved. Material data were analyzed by calculating means, medians, standard deviations, and ranges for 161 dental students screened by this casual and random self-monitoring of blood glucose levels as described by the American Diabetes Association’s 2008 Standards of Medical Care in Diabetes. Three types of data were assessed in this study. The first was the casual blood glucose levels of second-year dental students. The second was the data retrieved from student questionnaires regarding the value of teaching casual random blood glucose screening. The third was the U.S. dental schools’ responses regarding inclusion of casual blood glucose screening in their current curricula. Second-year dental students self-reported hypoglycemia in three instances and hyperglycemia in eight, based on current American Diabetes Association standards. Students agreed or strongly agreed that the value of teaching was informative (92.3 percent), beneficial (95 percent), and something that might be included in their practices (78.2 percent), with 19.2 percent being neutral on the inclusion. Only six U.S. dental schools reported teaching casual random glucose screening

    Projections for future radiocarbon content in dissolved inorganic carbon in hardwater lakes: a retrospective approach

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    Inland water bodies contain significant amounts of carbon in the form of dissolved inorganic carbon (DIC) derived from a mixture of modern atmospheric and pre-aged sources, which needs to be considered in radiocarbon-based dating and natural isotope tracer studies. While reservoir effects in hardwater lakes are generally considered to be constant through time, a comparison of recent and historical DI14C data from 2013 and 1969 for Lake Constance reveals that this is not a valid assumption. We hypothesize that changes in atmospheric carbon contributions to lake water DIC have taken place due to anthropogenically forced eutrophication in the 20th century. A return to more oligotrophic conditions in the lake led to reoxygenation and enhanced terrigenous organic matter remineralization, contributing to lake water DIC. Such comparisons using DI14C measurements from different points in time enable nonlinear changes in lake water DIC source and signature to be disentangled from concurrent anthropogenically induced changes in atmospheric 14C. In the future, coeval changes in lake dynamics due to climate change are expected to further perturb these balances. Depending on the scenario, Lake Constance DI14C is projected to decrease from the 2013 measured value of 0.856 Fm to 0.54–0.62 Fm by the end of the century

    Potential Implications of a Special Safeguard Mechanism in the WTO: the Case of Wheat

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    The Special Safeguard Mechanism (SSM) was a key issue in the July 2008 failure to reach agreement in the WTO negotiations under the Doha Development Agenda. It includes both price (P-SSM) and quantity-triggered measures (Q-SSM). This paper uses a stochastic simulation model of the world wheat market to investigate the effects of policy makers implementing policies based on the SSM rules. As expected, implementation of the Q-SSM is found to reduce imports, raise domestic prices, and boost mean domestic production in the SSM regions. However, rather than insulating countries that use it from price volatility, it would actually increase domestic price volatility in developing countries, largely by restricting imports when domestic output is low and prices high. We estimate that implementation of the Q-SSM would shrink average wheat imports by nearly 50% in some regions, with world wheat trade falling by 4.7%. The P-SSM is discriminatory against low price, developing country exporters and tends to contribute to additional producer price instability.Safeguard, SSM, WTO, volatility, wheat, food security, Agricultural and Food Policy, International Development, Q1, Q17, Q18,
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