We examine the survival of young scientists in academe. The propensity to leave follows an inverse u-shape. Publishing increases and patenting decreases the chance of survival. Scientists with strong preferences for business are less likely to stay in academe. 相似文献
This article provides an introduction to the Patstat patent database. It offers guided examples of 10 popular queries that are relevant for research purposes and that cover the most important data tables. It is targeted at academic researchers and practitioners who are willing to learn the basics of the database. 相似文献
This paper attempts to find a robust method of measuring competition when firms' operational activities are subject to frictions. The first part theoretically tests the indicative quality of two competition measures, the price‐cost margin (PCM) and the profit elasticity, in a model of monopolistic competition. The second part studies the empirical performance of the indices for a panel of Ukrainian manufacturing firms. This study offers a new approach to measuring profit elasticity that relies on structural estimation of a production function. The estimation methodology retrieves a productivity index that is adjusted to imperfect competition. The proposed method of measuring profit elasticity is found to be robust to frictions, but the PCM and traditional profit elasticity are biased, especially when the intensity of competition is low. Empirical findings show that competition exhibits a significantly positive correlation with aggregate productivity performance, while its impact on firm productivity is nonlinear. 相似文献
A consumer's web-browsing history, now readily available, may be much more useful than demographics for both targeting advertisements and personalizing prices. Using a method that combines economic modeling and machine learning methods, I find a striking difference. Personalizing prices based on web-browsing histories increases profits by 12.99%. Using demographics alone to personalize prices raises profits by only 0.25%, suggesting the percent profit gain from personalized pricing has increased 50-fold. I then investigate whether regulations intended to prevent price gouging increase aggregate consumer surplus. Two feasible regulations considered offer at best modest improvements. 相似文献
As market intermediaries, electricity suppliers purchase electricity from the wholesale market or self-generate to deliver their customers. However, electricity suppliers are uncertain about how much electricity their residential customers will use at any hour of the day until they actually turn switches on. While demand uncertainty is a common feature of all commodity markets, suppliers generally rely on storage to manage it. Singularly, electricity suppliers are exposed to joint volumetric and price risk on an hourly basis given the physical attributes of electricity. In the literature on electricity markets, few articles compare the efficiency of forward contracts, options and physical assets (i.e. power plants) within intraday hourly hedging portfolios, whereas electricity markets are precisely hourly markets. We analyse portfolios made of forwards, options and/or power plants for specific hourly clusters (9 am, 12 pm, 18 pm, 9 pm) based on electricity market data from 2013 to 2015 from the integrated German–Austrian spot market. Through a VaR model, we prove that intraday hedging with forwards is structurally inefficient compared to financial options and physical assets, no matter the cluster hour. Moreover, our results demonstrate the contribution of ‘out of the money’ options for all hours within volatile spot markets. 相似文献
Objectives: To examine treatment patterns, treatment effectiveness, and treatment costs for 1 year after patients with rheumatoid arthritis switched from a tumor necrosis factor inhibitor (TNFi) (adalimumab, certolizumab pegol, etanercept, golimumab, or infliximab), either cycling to another TNFi (“TNFi cyclers”) or switching to a new mechanism of action (abatacept, tocilizumab, or tofacitinib) (“new MOA switchers”).Methods: This retrospective cohort study used administrative claims data for a national insurer. Treatment persistence (without switching again, restarting, or discontinuing), treatment effectiveness (defined below), and costs were assessed for the 12-month post-switch period. Patients were “effectively treated” if they satisfied all six criteria for a treatment effectiveness algorithm (high adherence, no dose increase, no new conventional synthetic disease-modifying anti-rheumatic drug, no subsequent switch in therapy, no new/increased oral glucocorticoids, and <2 glucocorticoid injections). Multivariable logistic models were used to adjust for baseline factors.Results: The database included 581 new MOA switchers and 935 TNFi cyclers. New MOA switchers were 39% more likely than TNFi cyclers to persist after the switch (odds ratio [OR]?=?1.39; 95% confidence interval [CI]?=?1.12–1.74; p?=?.003) and 36% less likely to switch therapy again (OR?=?0.64; 95% CI?=?0.51–0.81; p?.001). New MOA switchers were 43% more likely than TNFi cyclers to be effectively treated (OR?=?1.43; 95% CI?=?1.11–1.85; p?=?.006). New MOA switchers had 16% lower drug costs than TNFi cyclers (cost ratio?=?0.84; 95% CI?=?0.79–0.88; p?.001) and 11% lower total costs of rheumatoid arthritis-related medical care (cost ratio?=?0.89; 95% CI?=?0.84–0.94; p?.001).Limitations: Claims payments may not reflect rebates or other cost offsets. Medical and pharmacy claims do not include clinical end-points or reasons that lead to new MOA switching vs TNFi cycling.Conclusions: These results support switching to a new MOA after a patient fails treatment with a TNFi, which is consistent with recent guidelines for the pharmacologic management of established rheumatoid arthritis. 相似文献
Aims: Data highlighting the cost drivers for non-valvular atrial fibrillation (NVAF) patients in terms of vitamin K antagonist (VKA) treatment and monitoring are lacking in France. This study aimed to evaluate the real-life daily cost of VKA treatment in 2013, in French patients suffering from NVAF.
Methods: This longitudinal observational study was performed using the EGB (Echantillon Généraliste des Bénéficiaires) database, a random sample of the French national insurance (NHI) database, which covers 80% of the population. All adult patients whose first NVAF anticoagulant treatment in 2013 was a VKA were analyzed. Costs were calculated for the duration of follow-up and then divided by the number of days of therapy. The analysis was performed both from the French NHI perspective (amount reimbursed by the NHI) and from a collective perspective.
Results: In this study, 3,254 NVAF patients treated with VKA in 2013 were included, and this sample comprised 52.6% males. The mean daily cost of VKA treatment was €1.13 (±1.18) according to the collective perspective (89.4% of this cost was associated to INR measurement) and €1.05 (±1.16) according to the NHI perspective.
Limitations: As diagnoses associated with procedures are not available in the EGB database, proxies were used, and an algorithm was created to define the AF population.
Conclusions: This analysis is the first to consider an exhaustive spectrum of the costs of VKA treatment in France using EGB data. VKA medication requires exhaustive follow-up, and, thus, associated costs are important. The results of the present study confirmed this close follow-up for VKA patients, making the cost of treatment by VKA nearly 10-times more expensive than the cost of medication itself. 相似文献
The existing literature on Islamic economics suggests that Islamic economics is a twentieth-century phenomenon with its roots in medieval Islamic intellectual and theological history, thereby leaving a centuries-long gap in the history of Islamic economic thinking. This study aims at taking a first step towards filling this gap by examining a nineteenth-century example of Islamic economics in late Ottoman economic literature. Suggesting a broader definition of Islamic economics, this article investigates a prominent Ottoman intellectual's efforts to define, reveal, and revive a tradition of Islamic economics in historical and intellectual context. 相似文献
A wealth of studies have contributed to the literature on gender differences in entrepreneurial success, but most lack key controls that aid in determining that success. Scale of the entrepreneur’s business is often not accounted for, and no studies to the author’s knowledge approach the gender comparison by specifically utilizing a sample of entrepreneur-only managed businesses. This allows for a direct comparison between individual entrepreneurs’ performance by gender, without the confounding heterogeneity that workforces may introduce. Data are taken from a national US survey of individuals, and model specifications include a number of important but oftentimes unavailable controls that have never before been used in conjunction. Female and male entrepreneurial success are statistically equal after controlling for risk preferences, intelligence, start-up capital, prior industry experience and hours worked at the business. Alternative specifications and sensitivity checks confirm and expand on these results. 相似文献