Timing and duration effects in residence histories and other longitudinal data: I. Stochastic and statistical models

A framework for studying the timing of events in migration histories and other micro-level longitudinal data is presented. The framework derives from a general stochastic model of the histories in which moves depend on the past history of the process, time varying individual characteristics, and exogenous constraints and opportunities. The semi-Markov model plays a distinguished role. The framework emphasizes the range of stochastic models available, the different types of time intervals and observational schemes that can be considered, distributions that can be used to characterize intervals, and statistical methodology. The use and crucial importance of the framework in empirical research is illustrated in the sequel.     

How companies tackle health care costs: Part I.

From the experience of a cross-section of Fortune "500" companies and top nonindustrials, these authors develop a profile of the newer types of health plans and benefits designed to cut health care costs. After examining the various plans, their funding, and their results, however, the authors conclude that another form of health insurance, more like other kinds of insurance policies that cover only catastrophic events, is the most promising from all points of view. In a second article, Regina Herzlinger will examine corporate efforts to reshape the system of supplying health care.     

Scharfe untere und obere Schranken für die Wahrscheinlichkeit der Realisation vonk untern Ereignissen

Summary LetA ₁,...,A _n be events in a probability space (RDER="0">,A,W). We denote byL _k the event, that at leastk events among then eventsA ₁,...A _n occur, and byK _k the event, that exactlyk events occur. If only the inequalities RDER="0"> _i RDER="0">W(A _i )RDER="0">RDER="0"> _i ,i=1,...,n, are known, we calculate sharp lower and upper bounds forW(L _k ) andW(K _k ). These bounds only depend onn, k and RDER="0"> _i ,RDER="0"> _i ,i=1,...,n. They are relevant, when treating combined tests or confidence procedures.