Distribution and expectation bounds on order statistics from possibly dependent variates

Abstract

Let X1,X2,...,Xn be n random variables with an arbitrary n-variate distribution. We say that the X's are maximally (resp. minimally) stable of order j(j∈{1,2,...,n}), if the distribution F(j) of max{Xk1,...,Xkj} (resp. G(j) of min{Xk1,...,Xkj}) is the same, for any j-subset {k1,...,kj} of {1,2,...,n}. Under the assumption of maximal (resp. minimal) stability of order j, sharp upper (resp. lower) bounds are given for the distribution Fk:n of the kth order statistic Xk:n, in terms of F(j) (resp. G(j)), and the corresponding expectation bounds are derived. Moreover, some expectation bounds in the case of j-independent-F samples (i.e., when each j-tuple Xk1,...,Xkj is independent with a common marginal distribution F) are given. © 2001 Elsevier Science B.V.