BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20260602T200405EDT-1861BKJufH@132.216.98.100 DTSTAMP:20260603T000405Z DESCRIPTION:Title: Learning from a Biased Sample\n\nAbstract: The empirical risk minimization approach to data-driven decision making assumes that we can learn a decision rule from training data drawn under the same conditi ons as the ones we want to deploy it under. However\, in a number of setti ngs\, we may be concerned that our training sample is biased\, and that so me groups (characterized by either observable or unobservable attributes) may be under- or over-represented relative to the general population\; and in this setting empirical risk minimization over the training set may fai l to yield rules that perform well at deployment. Building on concepts fro m distributionally robust optimization and sensitivity analysis\, we propo se a method for learning a decision rule that minimizes the worst-case ris k incurred under a family of test distributions whose conditional distribu tions of outcomes  given covariates  differ from the conditional training distribution by at most a constant factor\, and whose covariate distributi ons are absolutely continuous with respect to the covariate distribution o f the training data. We apply a result of Rockafellar and Uryasev to show that this problem is equivalent to an augmented convex risk minimization p roblem. We give statistical guarantees for learning a robust model using t he method of sieves and propose a deep learning algorithm whose loss funct ion captures our robustness target. We empirically validate our proposed m ethod in simulations and a case study with the MIMIC-III dataset.\n \n Paper link: https://arxiv.org/abs/2209.01754\n\nWeb site : https://mcgillstat.g ithub.io\n DTSTART:20230203T203000Z DTEND:20230203T213000Z SUMMARY:Lihua Lei\, Stanford Graduate School of Business URL:/mathstat/channels/event/lihua-lei-stanford-gradua te-school-business-345745 END:VEVENT END:VCALENDAR