Optimal grading contests

We study the design of grading contests between agents with private information about their abilities under the assumption that the value of a grade is determined by the information it reveals about the agent's productivity. Towards the goal of identifying the effort-maximizing grading contest, we study the effect of increasing prizes and increasing competition on effort and find that the effects depend qualitatively on the distribution of abilities in the population. Consequently, while the optimal grading contest always uniquely identifies the best performing agent, it may want to pool or separate the remaining agents depending upon the distribution. We identify sufficient conditions under which a rank-revealing grading contest, a leaderboard-with-cutoff type grading contest, and a coarse grading contest with at most three grades are optimal. In the process, we also identify distributions under which there is a monotonic relationship between the informativeness of a grading scheme and the effort induced by it.Comment: 25 page

Optimal tie-breaking rules

We consider two-player contests with the possibility of ties and study the effect of different tie-breaking rules on effort. For ratio-form and difference-form contests that admit pure-strategy Nash equilibrium, we find that the effort of both players is monotone decreasing in the probability that ties are broken in favor of the stronger player. Thus, the effort-maximizing tie-breaking rule commits to breaking ties in favor of the weaker agent. With symmetric agents, we find that the equilibrium is generally symmetric and independent of the tie-breaking rule. We also study the design of random tie-breaking rules that are ex-ante fair and identify sufficient conditions under which breaking ties before the contest actually leads to greater expected effort than the more commonly observed practice of breaking ties after the contest.Comment: 25 page

Essays in Mechanism Design and Contest Theory

This dissertation contains three essays. They offer contributions to the fields of mechanism design (Chapters 1 and 2) and contest theory (Chapter 3). Chapter 1, co-authored with Wade Hann-Caruthers, studies the problem of aggregating privately-held preferences for a facility to be located on a plane. We show that for a large class of social cost functions, the mechanism that locates the facility at the coordinate-wise median of the agent’s ideal points is quantitatively optimal (in the sense that it has the smallest worst-case approximation ratio) among all deterministic, anonymous, and incentive-compatible mechanisms. We also obtain bounds on the worst-case approximation ratio of the coordinate-wise median mechanism for an important subclass of social cost functions. Chapter 2, co-authored with Wade Hann-Caruthers, studies a principal-agent project selection problem with asymmetric information and demonstrates the value for the principal in inducing partial verifiability constraints, such as no-overselling, on the agent. We consider a setting where the principal has to choose one among a set of available projects but the relevant information, such as each project's profitability, is held by a self-interested agent who might also have its own preference over the projects. If the agent is unconstrained in its ability to manipulate its private information, the principal can do no better than randomly choosing a project. But if the agent cannot oversell any of the projects, maybe because it must support its claims with evidence, we show that a simple cutoff mechanism (agent's favorite project is chosen among those that meet a cutoff profit level and a default project) is optimal for the principal. We also find evidence in support of the well-known ally-principle which says that principal delegates more authority to an agent with more aligned preferences. Chapter 3 studies the effect of increasing the value of prizes and competitiveness of contests on the effort exerted by participants in an incomplete information environment. We identify two natural sufficient conditions on the distribution of abilities in the population under which the interventions have opposite effects on effort. We also discuss applications to the design of optimal contests in three different environments, including the design of grading contests. Assuming that the value of a grade is determined by the information it reveals about the agent's ability, we establish a link between the informativeness of a grading scheme and the effort induced by it.</p

A perspective on SARS-CoV-2 and community transmission in the top COVID-19 affected nations

In most countries, during the initial months of the COVID-19 outbreak resources were directed to mitigation measures that prevented severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission from symptomatic individuals. The coverage of the pre-symptomatic and asymptomatic individuals' testing required intensive clinical sampling along with rigorous symptom-based screening. Based on the SARS-CoV-2 transmission, the disease outbreak across nations was divided into four distinct stages: (i) epidemic, (ii) community transmission, (iii) local transmission, and (iv) imported cases. Here we discuss the COVID-19 community transmission stage for the top ten COVID-19 affected nations. Epidemic dynamics and policies implemented to contain the spread of SARS-CoV-2 infection varied globally. Further, the mitigation strategies and related health policies for dealing with the pandemic were based on the stages of transmission of the disease. We suggest that correctly identifying the transmission stage during a pandemic ensures the implementation of mitigation strategies. Thus prompt analysis of the status of COVID-19 transmission stage(s) in any nation seems crucial to direct health policies accordingly

Aesthetic and functional rehabilitation of missing teeth in growing patients with mini-implants: a contemporary approach

Growing patients with missing teeth in aesthetically prominent areas pose a challenge in restoration of the same. Fracture of anterior teeth in these age groups is very common and often requires removal of the affected tooth. After the decision to maintain the space in the dental arch is made, some other factors have to be borne in mind before restoration of the space. Continuing growth of the alveolar bones, questionable cooperation of the patient and aesthetics are deciding factors that may limit the treatment options. The effective use of mini-implants for space preservation, alveolar bone width maintenance and aesthetics represents an elective way of successfully treating such cases. The aim of this article is to describe as well as highlight the advantages and ease of the procedure with the help of two clinical cases

Botulinum toxin: a boon or bane in dentistry

Botulinum toxin is a neurotoxin which is produced by the Clostridium botulinum bacteria. It is an anaerobic, gram-positive, spore-forming rod-shaped bacteria which is commonly found in soil, on plants, in water and in the intestinal tracts of animals. All the serotypes of botulinum toxin interfere with neural transmission by blocking the release of acetylcholine. The use of botulinum toxins has revolutionised the treatment of various ophthalmic spastic disorders, Orofacial pain conditions, facial dystonia and periocular wrinkles. A precise knowledge and understanding of the functional anatomy of the mimetic muscles is absolutely necessary to correctly use botulinum toxins in clinical practice. This article is an effort to understand Botulinum toxin and its applications in head and neck

Review: recent trends in management of oral lichen planus

Oral lichen planus (OLP) is a chronic mucocutaneous inflammatory disease, associated with altered cell‐mediated immunological function. It has been characterised by long‐term evolution, repeated exacerbations, sometimes painful and resistant to treatment, or even all of these. OLP significantly affects quality of patient's life. There is a higher risk of malignant transformation accompanied with OLP and similar appearing oral lichenoid lesions. Current OLP therapy aims at eliminating all mucosal‐related lesions reduce symptomatology and decrease the risk of oral cancer. This review summarizes recent treatment modalities used in the management of OLP which includes corticosteroids, immunomodulatory agents, retinoids, ultraviolet irradiation and/or laser therapy, herbal remedies. In addition, focus is also given upon adopting holistic approach in such patients by emphasizing on stress management

The profiles of first and second SARS-CoV-2 waves in the top ten COVID-19 affected countries

In March 2020, the World Health Organization (WHO) acknowledged the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as a "public health emergency of international concern." Within a month, coronavirus disease 2019 (COVID-19) was declared a pandemic. As of 21 July 2021, 192.8 million cases and 4.13 million deaths have been attributed to COVID-19 worldwide. Here we discuss the data from top ten COVID-19 affected countries, with an emphasis on the average strolling period of 6 to 8 months between first and second wave in these nations. Our study ascertains that analysis of the data from countries temporally ahead of others during the pandemic gives policymakers the chance to strategize and postpone or mitigate subsequent COVID-19 waves. With governments throughout the globe continuing their immunisation efforts, a study of the key indicators of COVID-19 waves from the top ten countries is critical to preparing the healthcare system to save millions of lives

Comparative evaluation of autologous platelet rich plasma and triamcinolone acetonide injection in the management of erosive lichen planus and oral submucous fibrosis: a clinical study

Background: It is need of an hour to establish an effective and efficient treatment modality for OLP and OSMF with lesser or no adverse effects. Platelet rich plasma can be used in mucosal lesions as it has a high concentration of various growth factors and anti-inflammatory properties. It could be a better novel substitute to the corticosteroid without any side effects. The present study is an effort to evaluate the therapeutic effects of intralesional injection of PRP in oral erosive lichen planus and OSMF compared to intralesional corticosteroids in the same patient. Methods: It was a randomized controlled clinical study consisting of 40 patients between the age groups of 18-60 years visiting dental OPD diagnosed clinically with either erosive lichen planus or OSMF. Triamcinolone 40 mg(1mg/ml) mixed with 2% (1:80,000) lignocaine hydrochloride was injected into the lesion on one side in case of erosive lichen planus and into the submucosal plane and fibrous bands in case of OSMF patients. Autologous PRP was prepared and injected on the other side in same patients. At every visit, all the patients were evaluated for pain and burning sensations, size, and severity of the lesion, and interincisal mouth opening (mm). The parameters were measured and recorded during the patient’s every visit. All the results were obtained and statically analyzed. Results: Intralesional injections of triamcinolone acetonide and PRP are effective in reducing pain and burning sensation in OSMF, but PRP is less effective in improving cheek flexibility as compared to triamcinolone acetonide. In OLP, both triamcinolone acetonide and PRP are almost equally effective in reducing the size of the lesion. However, PRP shows slightly better results in reducing the severity of the lesion and in pain and burning sensation in the patients of OLP as compared to intralesional triamcinolone acetonide. Conclusions: Thus, PRP is an effective modality in treating both OSMF and oral erosive lichen planus with no adverse effects