BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20260603T005924EDT-2779CXi8TV@132.216.98.100 DTSTAMP:20260603T045924Z DESCRIPTION:Title: Learning from a Biased Sample.\n\nAbstract:\n\nAbstract: \n\nThe empirical risk minimization approach to data-driven decision makin g assumes that we can learn a decision rule from training data drawn under the same conditions as the ones we want to deploy it under. However\, in a number of settings\, we may be concerned that our training sample is bia sed\, and that some groups (characterized by either observable or unobserv able attributes) may be under- or over-represented relative to the general population\; and in this setting empirical risk minimization over the tra ining set may fail to yield rules that perform well at deployment. Buildin g on concepts from distributionally robust optimization and sensitivity an alysis\, we propose a method for learning a decision rule that minimizes t he worst-case risk incurred under a family of test distributions whose con ditional distributions of outcomes given covariates differ from the condit ional training distribution by at most a constant factor\, and whose covar iate distributions are absolutely continuous with respect to the covariate distribution of the training data. We apply a result of Rockafellar and U ryasev to show that this problem is equivalent to an augmented convex risk minimization problem. We give statistical guarantees for learning a robus t model using the method of sieves and propose a deep learning algorithm w hose loss function captures our robustness target. We empirically validate our proposed method in simulations and a case study with the MIMIC-III da taset.\n\n\n https://mcgill.zoom.us/j/83436686293?pwd=b0RmWmlXRXE3OWR6NlNIc WF5d0dJQT09\n\n\n \n\n\n Meeting ID: 834 3668 6293\n\n\n \n\n\n Passcode: 12 345\n\n\n \n\n\n \n \n \n  \n\n  \n \n \n \n\n DTSTART:20230203T203000Z DTEND:20230203T213000Z SUMMARY:Lihua Lei (at Stanford Graduate School of Business) URL:/mathstat/channels/event/lihua-lei-stanford-gradua te-school-business-345651 END:VEVENT END:VCALENDAR