Momentum and Social Learning in Presidential Primaries

This paper provides an investigation of the role of momentum and social learning in sequential voting systems. In the econometric model, voters are uncertain over candidate quality, and voters in late states attempt to infer the information held by those in early states from voting returns. Candidates experience momentum effects when their performance in early states exceeds expectations. The empirical application focuses on the responses of daily polling data to the release of voting returns in the 2004 presidential primary. We find that Kerry benefited from surprising wins in early states and took votes away from Dean, who held a strong lead prior to the beginning of the primary season. The voting weights implied by the estimated model demonstrate that early voters have up to 20 times the influence of late voters in the selection of candidates, demonstrating a significant departure from the ideal of "one person, one vote." We then address several alternative, non-learning explanations for our results. Finally, we run simulations under different electoral structures and find that a simultaneous election would have been more competitive due to the absence of herding and that alternative sequential structures would have yielded different outcomes.

Spatial Competition and Cross-border Shopping: Evidence from State Lotteries

This paper investigates competition between jurisdictions in the context of cross-border shopping for state lottery tickets. We first develop a simple theoretical model in which consumers choose between state lotteries and face a trade-off between travel costs and the price of a fair gamble, which is declining in the size of the jackpot and the odds of winning. Given this trade-off, the model predicts that per-resident sales should be more responsive to prices in small states with densely populated borders, relative to large states with sparsely populated borders. Our empirical analysis focuses on the multi-state games of Powerball and Mega Millions, and the identification strategy is based upon high-frequency variation in prices due to the rollover feature of lottery jackpots. The empirical results support the predictions of the model. The magnitude of these effects is large, suggesting that states do face competitive pressures from neighboring lotteries, but the effects vary significantly across states.

Delivery in the city: evidence on monopolistic competition from New York restaurants

We examine the response to entry in a large market with differentiated products using a novel longitudinal dataset of over 550,000 New York City restaurant menus from 68 consecutive weeks. We compare “treated” restaurants facing a nearby entrant to “control” restaurants with no new competition, matching restaurants using location characteristics and a pairwise distance measure based on menu text. Restaurants frequently adjust prices and product offerings, but we find no evidence that they respond differentially to new competition. However, restaurants in the top entry decile are 5% more likely to exit after a year than restaurants in the lowest entry decile

The Structure and Growth of Ethnic Neighborhoods

We introduce a new statistical definition of an immigrant ethnic neighborhood based on a choice model and using the location distribution of natives as a benchmark. We then examine the characteristics of ethnic neighborhoods in the United States using decadal census tract data from 1970-2010. We find that ethnic neighborhoods are pervasive, often capturing more than 50% of the ethnic population in a city, and differ significantly in housing and demographic characteristics from other locations in the city where a group lives. Most neighborhoods disappear within one or two decades. However, larger neighborhoods persist longer and have a well-defined spatial structure with negative population gradients. Neighborhoods grow primarily through spatial expansion into adjacent locations and lagged measures of the housing stock from previous decades can predict into which specific locations a neighborhood grows. Maps of ethnic neighborhoods: https://nathanschiff.shinyapps.io/ee_maps_deployed

Delivery in the city: evidence on monopolistic competition from New York restaurants

We examine the response to entry in a large market with differentiated products using a novel longitudinal dataset of over 550,000 New York City restaurant menus from 68 consecutive weeks. We compare “treated” restaurants facing a nearby entrant to “control” restaurants with no new competition, matching restaurants using location characteristics and a pairwise distance measure based on menu text. Restaurants frequently adjust prices and product offerings, but we find no evidence that they respond differentially to new competition. However, restaurants in the top entry decile are 5% more likely to exit after a year than restaurants in the lowest entry decile

Safety Recommendations for Evaluation and Surgery of the Head and Neck During the COVID-19 Pandemic

Importance The rapidly expanding novel coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2, has challenged the medical community to an unprecedented degree. Physicians and health care workers are at added risk of exposure and infection during the course of patient care. Because of the rapid spread of this disease through respiratory droplets, health care workers who come in close contact with the upper aerodigestive tract during diagnostic and therapeutic procedures, such as otolaryngologists–head and neck surgeons, are particularly at risk. A set of safety recommendations was created based on a review of the literature and communications with physicians with firsthand knowledge of safety procedures during the COVID-19 pandemic. Observations A high number of health care workers were infected during the first phase of the pandemic in the city of Wuhan, China. Subsequently, by adopting strict safety precautions, other regions were able to achieve high levels of safety for health care workers without jeopardizing the care of patients. The most common procedures related to the examination and treatment of upper aerodigestive tract diseases were reviewed. Each category was reviewed based on the potential risk imposed to health care workers. Specific recommendations were made based on the literature, when available, or consensus best practices. Specific safety recommendations were made for performing tracheostomy in patients with COVID-19. Conclusions and Relevance Preserving a highly skilled health care workforce is a top priority for any community and health care system. Based on the experience of health care systems in Asia and Europe, by following strict safety guidelines, the risk of exposure and infection of health care workers could be greatly reduced while providing high levels of care. The provided recommendations, which may evolve over time, could be used as broad guidance for all health care workers who are involved in the care of patients with COVID-19

Risk, Cooperation and the Economic origins of social Trust: an empirical Investigation

Extensive research has documented the importance of social trust for economic development, yet the origins of trust remain largely unexplored. This paper examines the historical relationship between risk, cooperation and the emergence of social trust. I hypothesize that norms of trust developed in preindustrial times as a result of experiences of collective action and mutual insurance triggered by the need for subsistence farmers to cope with climatic risk. These norms persisted over time, even after climate had become largely unimportant for economic activity. I test this hypothesis in the context of Europe combining high-resolution climate data for the period 1500-2000 with contemporary survey data at the sub-national level. I find that regions characterized by higher year-to-year variability in precipitation and temperature display higher levels of trust. Consistent with a theory of insurance through geographic differentiation, I also find that trust is higher in regions with more spatially heterogeneous precipitation. Furthermore, variation in social trust is driven by weather patterns during the growing season and by historical rather than recent variability. These results are robust to the inclusion of country fixed-effects, a variety of geographical controls, and regional measures of early political and economic development

Incorporating Medication Indications into the Prescribing Process

Purpose The incorporation of medication indications into the prescribing process to improve patient safety is discussed. Summary Currently, most prescriptions lack a key piece of information needed for safe medication use: the patient-specific drug indication. Integrating indications could pave the way for safer prescribing in multiple ways, including avoiding look-alike/sound-alike errors, facilitating selection of drugs of choice, aiding in communication among the healthcare team, bolstering patient understanding and adherence, and organizing medication lists to facilitate medication reconciliation. Although strongly supported by pharmacists, multiple prior attempts to encourage prescribers to include the indication on prescriptions have not been successful. We convened 6 expert panels to consult high-level stakeholders on system design considerations and requirements necessary for building and implementing an indications-based computerized prescriber order-entry (CPOE) system. We summarize our findings from the 6 expert stakeholder panels, including rationale, literature findings, potential benefits, and challenges of incorporating indications into the prescribing process. Based on this stakeholder input, design requirements for a new CPOE interface and workflow have been identified. Conclusion The emergence of universal electronic prescribing and content knowledge vendors has laid the groundwork for incorporating indications into the CPOE prescribing process. As medication prescribing moves in the direction of inclusion of the indication, it is imperative to design CPOE systems to efficiently and effectively incorporate indications into prescriber workflows and optimize ways this can best be accomplished

Measurement of the Electric and Magnetic Polarizabilities of the Proton

The Compton scattering cross section on the proton has been measured at laboratory angles of 90$^\circ$ and 135$^\circ$ using tagged photons in the energy range 70--100 MeV and simultaneously using untagged photons in the range 100--148~MeV. With the aid of dispersion relations, these cross sections were used to extract the electric and magnetic polarizabilities, $\bar{\alpha}$ and $\bar{\beta}$ respectively, of the proton. We find $$\bar{\alpha}+\bar{\beta} = ( 15.0 \pm 2.9 \pm 1.1 \pm 0.4 ) \times 10^{-4} \: {\rm fm}^3,$$ in agreement with a model-independent dispersion sum rule, and $$\bar{\alpha}-\bar{\beta} = ( 10.8 \pm 1.1 \pm 1.4 \pm 1.0 ) \times 10^{-4} \: {\rm fm}^3,$$ where the errors shown are statistical, systematic, and model-dependent, respectively. A comparison with previous experiments is given and global values for the polarizabilities are extracted.Comment: 35 pages, 11 PostScript figures, uses RevTex 3.

International practice patterns and factors associated with non-conventional hemodialysis utilization

<p>Abstract</p> <p>Background</p> <p>The purpose of our study was to determine characteristics that influence the utilization of non-conventional hemodialysis (NCHD) therapies and its subtypes (nocturnal (NHD), short daily (SDHD), long conventional (LCHD) and conventional hemodialysis (CHD) as well as provider attitudes regarding the evidence for NCHD use.</p> <p>Methods</p> <p>An international cohort of subscribers of a nephrology education website <url>http://www.nephrologynow.com</url> was invited to participate in an online survey. Non-conventional hemodialysis was defined as any forms of hemodialysis delivered > 3 treatments per week and/or > 4 hours per session. NHD and SDHD included both home and in-centre. Respondents were categorized as CHD if their centre only offered conventional thrice weekly hemodialysis. Variables associated with NCHD and its subtypes were determined using multivariate logistic regression analysis. The survey assessed multiple domains regarding NCHD including reasons for initiating and discontinuing, for not offering and attitudes regarding evidence.</p> <p>Results</p> <p>544 surveys were completed leading to a 15.6% response rate. The final cohort was limited to 311 physicians. Dialysis modalities utilized among the respondents were as follows: NCHD194 (62.4%), NHD 83 (26.7%), SDHD 107 (34.4%), LCHD 81 (26%) and CHD 117 (37.6%). The geographic regions of participants were as follows: 11.9% Canada, 26.7% USA, 21.5% Europe, 6.1% Australia/New Zealand, 10% Africa/Middle East, 10.9% Asia and 12.9% South America. Variables associated with NCHD utilization included NCHD training (OR 2.47 CI 1.25-4.16), government physician reimbursement (OR 2.66, CI 1.11-6.40), practicing at an academic centre (OR 2.28 CI 1.25-4.16), higher national health care expenditure and number of ESRD patients per centre. Hemodialysis providers with patients on NCHD were significantly more likely to agree with the statements that NCHD improves quality of life, improves nutritional status, reduces EPO requirements and is cost effective. The most common reasons to initiate NCHD were driven by patient preference and the desire to improve volume control and global health outcomes.</p> <p>Conclusion</p> <p>Physician attitudes toward the evidence for NCHD differ significantly between NCHD providers and conventional HD providers. Interventions and health policy targeting these areas along with increased physician education and training in NCHD modalities may be effective in increasing its utilization.</p