%0 Journal Article
%T Second-order asymptotic expansion for a non-synchronous covariation estimator
%A Arnak Dalalyan
%A Nakahiro Yoshida
%J Mathematics
%D 2008
%I arXiv
%R 10.1214/10-AIHP383
%X In this paper, we consider the problem of estimating the covariation of two diffusion processes when observations are subject to non-synchronicity. Building on recent papers \cite{Hay-Yos03, Hay-Yos04}, we derive second-order asymptotic expansions for the distribution of the Hayashi-Yoshida estimator in a fairly general setup including random sampling schemes and non-anticipative random drifts. The key steps leading to our results are a second-order decomposition of the estimator's distribution in the Gaussian set-up, a stochastic decomposition of the estimator itself and an accurate evaluation of the Malliavin covariance. To give a concrete example, we compute the constants involved in the resulting expansions for the particular case of sampling scheme generated by two independent Poisson processes.
%U http://arxiv.org/abs/0804.0676v2