A comprehensive test of order choice theory: recent evidence from the NYSE

We perform a comprehensive test of order choice theory from a sample period when the NYSE trades in decimals and allows automatic executions. We analyze the decision to submit or cancel an order or to take no action. For submitted orders we distinguish order type (market vs. limit), order side (buy vs. sell), execution method (floor vs. automatic), and order pricing aggressiveness. We use a multinomial logit specification and a new statistical test. We find a negative autocorrelation in changes in order flow exists over five-minute intervals supporting dynamic limit order book theory, despite a positive first-order autocorrelation in order type. Orders routed to the NYSE’s floor are sensitive to market conditions (e.g., spread, depth, volume, volatility, market and individual-stock returns, and private information), but those using the automatic execution system (Direct+) are insensitive to market conditions. When the quoted depth is large, traders are more likely to “jump the queue” by submitting limit orders with limit prices bettering existing quotes. Aggressively-priced limit orders are more likely late in the trading day providing evidence in support of prior experimental results

Pumpable two-part resin cable bolt bonding material tests

The Australian underground mining industry extensively uses thixotropic cementitious grout as a bonding agent for cable bolts. Grout is very effective as a bonding agent but is prone to issues with consistently achieving full column encapsulation and has operational issues impacting production. An economically viable two-part resin bonding agent is being investigated by Jennmar which offers some operational advantages. This paper explores the bond strength evaluation of the two-part resin against cementitious grout

An Integrated Model of Market and Limit Orders

Market Order, Limit Order, informed trading, market maker

Development, trials and testing of an innovative method to improve strength characteristics of hollow cable bolts

The 70 t Sumo is a resin point-anchored, pre-tensioned, post-grouted hollow cable bolt for tunnel roof support, particularly in poor ground conditions. An innovative ancillary product to the 70 t Sumo is the Booster cable, which is designed to reinforce the Sumo and enhance the systems shear and tensile performance. The Booster cable is an 11 mm 7-wire PC strand with a nominal breaking load of 15 tonnes, which is inserted into the hollow centre tube of the 70 t Sumo after grouting, while the grout is still pliable. Theoretically, the Booster can increase the tensile and shear capacity of the 70 t Sumo by up to 20%. The Booster reinforced 70 t Sumo is useful in high demand conditions where additional support strength is required without the need to install new support. This paper will present results from laboratory tests undertaken to quantify the tensile and shear characteristics of the 70 t Sumo reinforced with the Booster cable. A case study of a support trial using Booster reinforced 70 t Sumo cable bolts at a Dendrobium is also presented in this paper. The Booster cable successfully reduced 70 t Sumo cable bolt densities by 25%, from four cables per meter to three

Applying Structural Equation Modeling to Better Understand the Relationship Between Stressors, Social Support and Wellbeing in the Lives of Spouse Dementia Caregivers

Applying Structural Equation Modeling to Better Understand the Relationship Between Stressors, Social Support and Wellbeing in the Lives of Spouse Dementia Caregivers considers the utility of Pearlin et al.’s (1990) stress process model in understanding the needs of spouse caregivers. Data were drawn from eight biennial waves of the University of Michigan Health and Retirement Study (HRS) and analyzed using structural equation modeling. The final study sample comprised 774 spouses, average age 73, who were categorized based on Alzheimer’s Disease and Related Dementia (ADRD) and non-ADRD caregiver status. Results showed that for the study sample as a whole, social support mediated the negative effects of family conflict on both life satisfaction and loneliness experienced by caregivers. Social support did not, however, moderate caregiver strain. Economic problems were by far the most influential contextual factor for spouse caregivers. For ADRD caregivers, increased social support resulted in a much greater increase in life satisfaction compared to their non-ADRD counterparts. However social support did not reduce loneliness for ADRD caregivers (though it did for non-ADRD caregivers). The dominant source of secondary stress for ADRD caregivers was social constriction, whereas for non-ADRD spouse caregivers family conflict was the main source of secondary stress. These findings have useful implications for how informal caregiver support is arranged. For example, by developing interventions that capitalize on the role of social support in mediating the relationship between family conflict and caregiver wellbeing, and by more proactively addressing economic problems when implementing caregiver support interventions. These findings also indicate productive opportunities for future research, including longitudinal work to explore the relationship between stress, social support and caregiver wellbeing over time, and understanding more about differences in the experience of social constriction and family conflict between ADRD and non-ADRD caregivers

Association between insulin monotherapy versus insulin plus metformin and the risk of all-cause mortality and other serious outcomes: a retrospective cohort study

Aims To determine if concomitant metformin reduced the risk of death, major adverse cardiac events (MACE), and cancer in people with type 2 diabetes treated with insulin. Methods For this retrospective cohort study, people with type 2 diabetes who progressed to insulin with or without metformin from 2000 onwards were identified from the UK Clinical Practice Research Datalink (≈7% sample of the UK population). The risks of all-cause mortality, MACE and incident cancer were evaluated using multivariable Cox models comparing insulin monotherapy with insulin plus metformin. We accounted for insulin dose. Results 12,020 subjects treated with insulin were identified, including 6,484 treated with monotherapy. There were 1,486 deaths, 579 MACE (excluding those with a history of large vessel disease), and 680 cancer events (excluding those in patients with a history of cancer). Corresponding event rates were 41.5 (95% CI 39.4–43.6) deaths, 20.8 (19.2–22.5) MACE, and 21.6 (20.0–23.3) cancer events per 1,000 person-years. The adjusted hazard ratios (aHRs) for people prescribed insulin plus metformin versus insulin monotherapy were 0.60 (95% CI 0.52–0.68) for all-cause mortality, 0.75 (0.62–0.91) for MACE, and 0.96 (0.80–1.15) for cancer. For patients who were propensity-score matched, the corresponding aHRs for all-cause mortality and cancer were 0.62 (0.52–0.75) and 0.99 (0.78–1.26), respectively. For MACE, the aHR was 1.06 (0.75–1.49) prior to 1,275 days and 1.87 (1.22–2.86) after 1,275 days post-index. Conclusions People with type 2 diabetes treated with insulin plus concomitant metformin had a reduced risk of death and MACE compared with people treated with insulin monotherapy. There was no statistically significant difference in the risk of cancer between people treated with insulin as monotherapy or in combination with metformin

Avoiding disclosure of individually identifiable health information: a literature review

Achieving data and information dissemination without arming anyone is a central task of any entity in charge of collecting data. In this article, the authors examine the literature on data and statistical confidentiality. Rather than comparing the theoretical properties of specific methods, they emphasize the main themes that emerge from the ongoing discussion among scientists regarding how best to achieve the appropriate balance between data protection, data utility, and data dissemination. They cover the literature on de-identification and reidentification methods with emphasis on health care data. The authors also discuss the benefits and limitations for the most common access methods. Although there is abundant theoretical and empirical research, their review reveals lack of consensus on fundamental questions for empirical practice: How to assess disclosure risk, how to choose among disclosure methods, how to assess reidentification risk, and how to measure utility loss.public use files, disclosure avoidance, reidentification, de-identification, data utility

Evaluation of the incremental cost to the National Health Service of prescribing analogue insulin

Introduction Insulin analogues have become increasingly popular despite their greater cost compared with human insulin. The aim of this study was to calculate the incremental cost to the National Health Service (NHS) of prescribing analogue insulin preparations instead of their human insulin alternatives. Methods Open-source data from the four UK prescription pricing agencies from 2000 to 2009 were analysed. Cost was adjusted for inflation and reported in UK pounds at 2010 prices. Results Over the 10-year period, the NHS spent a total of £2732 million on insulin. The total annual cost increased from £156 million to £359 million, an increase of 130%. The annual cost of analogue insulin increased from £18.2 million (12% of total insulin cost) to £305 million (85% of total insulin cost), whereas the cost of human insulin decreased from £131 million (84% of total insulin cost) to £51 million (14% of total insulin cost). If it is assumed that all patients using insulin analogues could have received human insulin instead, the overall incremental cost of analogue insulin was £625 million. Conclusion Given the high marginal cost of analogue insulin, adherence to prescribing guidelines recommending the preferential use of human insulin would have resulted in considerable financial savings over the period