“…The functional q 2,0 is important in rank-based statistics where it appears, e.g., in many efficacy expressions (Gibbons and Chakraborti, 1992) and in the asymptotic variance of the Hodges-Lehmann estimator. Källberg et al (2013) study U -statistic estimators of q 2,0 and h 2 based on the number of ǫ-close observations in a sample from a stationary m-dependent sequence, and establish conditions for their consistency and weak convergence. In this paper, we investigate the corresponding U -statistic estimators for a more general class of functionals, including the (two-density) functional q 1,1 , and give alternative conditions for consistency.…”