30 research outputs found
Empirical study of link between operations and financial performance for retailers
Retailers continually try to improve their store operations in order to achieve better financial performance. However, there appears to be limited empirical research that shows the influence of operations management on financial performance. We conduct an empirical study of the link between operations management and financial performance of retailers by investigating at drivers of store level operations in a single retail chain, and studying the relative firm level performance of US public retailers. We utilize data from two sources; individual proprietary store level traffic data and publicly available financial data for this study. In addition, we complement our datasets by extracting information on demographics from publicly available databases. In the first chapter, we use detailed traffic data to study whether there is understaffing at a heterogeneous group in retail stores belonging to the same retail chain. We then look at some of the underlying causes for this understaffing, including traffic forecast errors and scheduling constraints, and quantify their impact on store profits. In the second chapter, we characterize the underlying distribution of hourly traffic data that is obtained with help of traffic counters at each of the retail stores and study the impact that competition and location demographics have on the observed variability in traffic. We then explore the managerial implications of having detailed traffic information on labor planning by deriving better forecasts of traffic that would aid staffing decisions. Finally, in the third chapter, we conduct a firm level analysis of US public retailers with help of benchmarking metrics developed from operations management. We demonstrate an inverted-U relationship between abnormal inventory growth and one-year ahead earnings. We also show that equity analysts are systematically biased in their earnings forecasts as they fail to incorporate information contained in abnormal inventory growth and further, an investment strategy based on abnormal inventory growth can yield significant abnormal returns
The Relationship Between Abnormal Inventory Growth and Future Earnings for U.S. Public Retailers
In this paper we examine the relationship between inventory levels and one-year ahead earnings of retailers using publicly available financial data. We use benchmarking metrics obtained from operations management literature to demonstrate an inverted-U relationship between abnormal inventory growth and one-year ahead earnings per share for retailers. We also find that equity analysts do not fully incorporate the information contained in abnormal inventory growth of retailers in their earnings forecasts resulting in systematic biases. Finally, we show that an investment strategy based on abnormal inventory growth yields abnormal returns of 11.8% (p<0.001)
Estimating the Impact of Understaffing on Sales and Profitability in Retail Stores
In this paper we use micro-level data on store traffic, sales and labor from 41 stores of a large retail chain to identify the extent of understaffing in retail stores and quantify its impact on sales and profitability. We show how traffic data can be leveraged in making staffing decisions through use of a structural model that captures the relationship between traffic, sales and labor. Assuming that store managers aim to maximize profits, we estimate the contribution of labor to sales and impute the cost of labor for each store in our sample. We find significant heterogeneity in the contribution of labor to sales as well as imputed cost of labor across these stores and across time. Using the estimated parameters, we establish the presence of systematic understaffing during peak hours. Aligning staffing levels with changing traffic patterns can result in a 6.15% savings in lost sales and a 5.74% improvement in profitability. We describe a pilot implementation of our approach at another large retailer where we identify periods of understaffing in their stores and document the impact on conversion rate and lost sales
A panel of microsatellites to individually identify leopards and its application to leopard monitoring in human dominated landscapes
<p>Abstract</p> <p>Background</p> <p>Leopards are the most widely distributed of the large cats, ranging from Africa to the Russian Far East. Because of habitat fragmentation, high human population densities and the inherent adaptability of this species, they now occupy landscapes close to human settlements. As a result, they are the most common species involved in human wildlife conflict in India, necessitating their monitoring. However, their elusive nature makes such monitoring difficult. Recent advances in DNA methods along with non-invasive sampling techniques can be used to monitor populations and individuals across large landscapes including human dominated ones. In this paper, we describe a DNA-based method for leopard individual identification where we used fecal DNA samples to obtain genetic material. Further, we apply our methods to non-invasive samples collected in a human-dominated landscape to estimate the minimum number of leopards in this human-leopard conflict area in Western India.</p> <p>Results</p> <p>In this study, 25 of the 29 tested cross-specific microsatellite markers showed positive amplification in 37 wild-caught leopards. These loci revealed varied levels of polymorphism (four-12 alleles) and heterozygosity (0.05-0.79). Combining data on amplification success (including non-invasive samples) and locus specific polymorphisms, we showed that eight loci provide a sibling probability of identity of 0.0005, suggesting that this panel can be used to discriminate individuals in the wild. When this microsatellite panel was applied to fecal samples collected from a human-dominated landscape, we identified 7 individuals, with a sibling probability of identity of 0.001. Amplification success of field collected scats was up to 72%, and genotype error ranged from 0-7.4%.</p> <p>Conclusion</p> <p>Our results demonstrated that the selected panel of eight microsatellite loci can conclusively identify leopards from various kinds of biological samples. Our methods can be used to monitor leopards over small and large landscapes to assess population trends, as well as could be tested for population assignment in forensic applications.</p
Carrier localization and electronic phase separation in a doped spin-orbit driven Mott phase in Sr3(Ir1-xRux)2O7
Interest in many strongly spin-orbit coupled 5d-transition metal oxide
insulators stems from mapping their electronic structures to a J=1/2 Mott
phase. One of the hopes is to establish their Mott parent states and explore
these systems' potential of realizing novel electronic states upon carrier
doping. However, once doped, little is understood regarding the role of their
reduced Coulomb interaction U relative to their strongly correlated 3d-electron
cousins. Here we show that, upon hole-doping a candidate J=1/2 Mott insulator,
carriers remain localized within a nanoscale phase separated ground state. A
percolative metal-insulator transition occurs with interplay between localized
and itinerant regions, stabilizing an antiferromagnetic metallic phase beyond
the critical region. Our results demonstrate a surprising parallel between
doped 5d- and 3d-electron Mott systems and suggest either through the near
degeneracy of nearby electronic phases or direct carrier localization that U is
essential to the carrier response of this doped spin-orbit Mott insulator.Comment: 25 pages, 4 figures in main text, 4 figures in supplemental tex
Burden of disease scenarios for 204 countries and territories, 2022â2050: a forecasting analysis for the Global Burden of Disease Study 2021
Background: Future trends in disease burden and drivers of health are of great interest to policy makers and the public at large. This information can be used for policy and long-term health investment, planning, and prioritisation. We have expanded and improved upon previous forecasts produced as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) and provide a reference forecast (the most likely future), and alternative scenarios assessing disease burden trajectories if selected sets of risk factors were eliminated from current levels by 2050. Methods: Using forecasts of major drivers of health such as the Socio-demographic Index (SDI; a composite measure of lag-distributed income per capita, mean years of education, and total fertility under 25 years of age) and the full set of risk factor exposures captured by GBD, we provide cause-specific forecasts of mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) by age and sex from 2022 to 2050 for 204 countries and territories, 21 GBD regions, seven super-regions, and the world. All analyses were done at the cause-specific level so that only risk factors deemed causal by the GBD comparative risk assessment influenced future trajectories of mortality for each disease. Cause-specific mortality was modelled using mixed-effects models with SDI and time as the main covariates, and the combined impact of causal risk factors as an offset in the model. At the all-cause mortality level, we captured unexplained variation by modelling residuals with an autoregressive integrated moving average model with drift attenuation. These all-cause forecasts constrained the cause-specific forecasts at successively deeper levels of the GBD cause hierarchy using cascading mortality models, thus ensuring a robust estimate of cause-specific mortality. For non-fatal measures (eg, low back pain), incidence and prevalence were forecasted from mixed-effects models with SDI as the main covariate, and YLDs were computed from the resulting prevalence forecasts and average disability weights from GBD. Alternative future scenarios were constructed by replacing appropriate reference trajectories for risk factors with hypothetical trajectories of gradual elimination of risk factor exposure from current levels to 2050. The scenarios were constructed from various sets of risk factors: environmental risks (Safer Environment scenario), risks associated with communicable, maternal, neonatal, and nutritional diseases (CMNNs; Improved Childhood Nutrition and Vaccination scenario), risks associated with major non-communicable diseases (NCDs; Improved Behavioural and Metabolic Risks scenario), and the combined effects of these three scenarios. Using the Shared Socioeconomic Pathways climate scenarios SSP2-4.5 as reference and SSP1-1.9 as an optimistic alternative in the Safer Environment scenario, we accounted for climate change impact on health by using the most recent Intergovernmental Panel on Climate Change temperature forecasts and published trajectories of ambient air pollution for the same two scenarios. Life expectancy and healthy life expectancy were computed using standard methods. The forecasting framework includes computing the age-sex-specific future population for each location and separately for each scenario. 95% uncertainty intervals (UIs) for each individual future estimate were derived from the 2·5th and 97·5th percentiles of distributions generated from propagating 500 draws through the multistage computational pipeline. Findings: In the reference scenario forecast, global and super-regional life expectancy increased from 2022 to 2050, but improvement was at a slower pace than in the three decades preceding the COVID-19 pandemic (beginning in 2020). Gains in future life expectancy were forecasted to be greatest in super-regions with comparatively low life expectancies (such as sub-Saharan Africa) compared with super-regions with higher life expectancies (such as the high-income super-region), leading to a trend towards convergence in life expectancy across locations between now and 2050. At the super-region level, forecasted healthy life expectancy patterns were similar to those of life expectancies. Forecasts for the reference scenario found that health will improve in the coming decades, with all-cause age-standardised DALY rates decreasing in every GBD super-region. The total DALY burden measured in counts, however, will increase in every super-region, largely a function of population ageing and growth. We also forecasted that both DALY counts and age-standardised DALY rates will continue to shift from CMNNs to NCDs, with the most pronounced shifts occurring in sub-Saharan Africa (60·1% [95% UI 56·8â63·1] of DALYs were from CMNNs in 2022 compared with 35·8% [31·0â45·0] in 2050) and south Asia (31·7% [29·2â34·1] to 15·5% [13·7â17·5]). This shift is reflected in the leading global causes of DALYs, with the top four causes in 2050 being ischaemic heart disease, stroke, diabetes, and chronic obstructive pulmonary disease, compared with 2022, with ischaemic heart disease, neonatal disorders, stroke, and lower respiratory infections at the top. The global proportion of DALYs due to YLDs likewise increased from 33·8% (27·4â40·3) to 41·1% (33·9â48·1) from 2022 to 2050, demonstrating an important shift in overall disease burden towards morbidity and away from premature death. The largest shift of this kind was forecasted for sub-Saharan Africa, from 20·1% (15·6â25·3) of DALYs due to YLDs in 2022 to 35·6% (26·5â43·0) in 2050. In the assessment of alternative future scenarios, the combined effects of the scenarios (Safer Environment, Improved Childhood Nutrition and Vaccination, and Improved Behavioural and Metabolic Risks scenarios) demonstrated an important decrease in the global burden of DALYs in 2050 of 15·4% (13·5â17·5) compared with the reference scenario, with decreases across super-regions ranging from 10·4% (9·7â11·3) in the high-income super-region to 23·9% (20·7â27·3) in north Africa and the Middle East. The Safer Environment scenario had its largest decrease in sub-Saharan Africa (5·2% [3·5â6·8]), the Improved Behavioural and Metabolic Risks scenario in north Africa and the Middle East (23·2% [20·2â26·5]), and the Improved Nutrition and Vaccination scenario in sub-Saharan Africa (2·0% [â0·6 to 3·6]). Interpretation: Globally, life expectancy and age-standardised disease burden were forecasted to improve between 2022 and 2050, with the majority of the burden continuing to shift from CMNNs to NCDs. That said, continued progress on reducing the CMNN disease burden will be dependent on maintaining investment in and policy emphasis on CMNN disease prevention and treatment. Mostly due to growth and ageing of populations, the number of deaths and DALYs due to all causes combined will generally increase. By constructing alternative future scenarios wherein certain risk exposures are eliminated by 2050, we have shown that opportunities exist to substantially improve health outcomes in the future through concerted efforts to prevent exposure to well established risk factors and to expand access to key health interventions
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 nonâcritically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (nâ=â257), ARB (nâ=â248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; nâ=â10), or no RAS inhibitor (control; nâ=â264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ supportâfree days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ supportâfree days among critically ill patients was 10 (â1 to 16) in the ACE inhibitor group (nâ=â231), 8 (â1 to 17) in the ARB group (nâ=â217), and 12 (0 to 17) in the control group (nâ=â231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ supportâfree days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
Empirical study of link between operations and financial performance for retailers
Retailers continually try to improve their store operations in order to achieve better financial performance. However, there appears to be limited empirical research that shows the influence of operations management on financial performance. We conduct an empirical study of the link between operations management and financial performance of retailers by investigating at drivers of store level operations in a single retail chain, and studying the relative firm level performance of US public retailers. We utilize data from two sources; individual proprietary store level traffic data and publicly available financial data for this study. In addition, we complement our datasets by extracting information on demographics from publicly available databases. In the first chapter, we use detailed traffic data to study whether there is understaffing at a heterogeneous group in retail stores belonging to the same retail chain. We then look at some of the underlying causes for this understaffing, including traffic forecast errors and scheduling constraints, and quantify their impact on store profits. In the second chapter, we characterize the underlying distribution of hourly traffic data that is obtained with help of traffic counters at each of the retail stores and study the impact that competition and location demographics have on the observed variability in traffic. We then explore the managerial implications of having detailed traffic information on labor planning by deriving better forecasts of traffic that would aid staffing decisions. Finally, in the third chapter, we conduct a firm level analysis of US public retailers with help of benchmarking metrics developed from operations management. We demonstrate an inverted-U relationship between abnormal inventory growth and one-year ahead earnings. We also show that equity analysts are systematically biased in their earnings forecasts as they fail to incorporate information contained in abnormal inventory growth and further, an investment strategy based on abnormal inventory growth can yield significant abnormal returns