BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20260605T171618EDT-4458Ma1AJm@132.216.98.100 DTSTAMP:20260605T211618Z DESCRIPTION:Efficient estimation in sub and full populations with monotonic ally missing at random data.\n\nWe consider estimation of a parameter defi ned by moment restrictions on a target population charac- terized by the m issingness pattern of monotonically missing at random data. Attrition or d ropout in a\, say\, R-period study/survey typically generates such data. I n this case\, a generic target is the underlying population of the sample units dropping out in contiguous periods a\, . . . \, b where a <= b in {1 \, . . . \, R}. The semiparametric efficiency bound and the efficient infl uence function are obtained for the parameter of interest from the generic target nesting the well-known special cases with (a = 1\, b = R) or (R = 2\, a = b = 1). Our results\, however\, differ fundamentally from the exis ting literature in that the consideration of a generic target beyond those special cases provides new insights on the usability and contribution of the sam- ple units toward efficient estimation. Efficient estimation turns out to be standard MINPIN estimation with asymptotic properties directly following from the well-known existing results. Further desirable properti es follow since the concerned MINPIN estimating functions are also doubly robust to parametric misspecifica- tion of the nonparametric nuisance comp onents. A Monte Carlo study demonstrates all these nice properties of the efficient estimator and the t-test based on it. A simple empirical illustr ation using the Project STAR data demonstrates substantive improvement in precision over the standard but inefficient estimators.We consider estimat ion of a parameter defined by moment restrictions on a target population c harac- terized by the missingness pattern of monotonically missing at rand om data. Attrition or dropout in a\, say\, R-period study/survey typically generates such data. In this case\, a generic target is the underlying po pulation of the sample units dropping out in contiguous periods a\, . . . \, b where a <= b in {1\, . . . \, R}. The semiparametric efficiency bound and the efficient influence function are obtained for the parameter of in terest from the generic target nesting the well-known special cases with ( a = 1\, b = R) or (R = 2\, a = b = 1). Our results\, however\, differ fund amentally from the existing literature in that the consideration of a gene ric target beyond those special cases provides new insights on the usabili ty and contribution of the sam- ple units toward efficient estimation. Eff icient estimation turns out to be standard MINPIN estimation with asymptot ic properties directly following from the well-known existing results. Fur ther desirable properties follow since the concerned MINPIN estimating fun ctions are also doubly robust to parametric misspecifica- tion of the nonp arametric nuisance components. A Monte Carlo study demonstrates all these nice properties of the efficient estimator and the t-test based on it. A s imple empirical illustration using the Project STAR data demonstrates subs tantive improvement in precision over the standard but inefficient estimat ors.\n DTSTART:20180321T193000Z DTEND:20180321T203000Z LOCATION:Room D-4\, CA\, QC\, J1K 2R1\, Université de Sherbrooke\, 2500 Bou l. de l'Université SUMMARY:Saraswata Chaudhuri\, Department of Economics\, 91ºÚÁÏÍø URL:/mathstat/channels/event/saraswata-chaudhuri-depar tment-economics-mcgill-university-285892 END:VEVENT END:VCALENDAR