“…Typically there is a very large drop in the sample size due to synchronisation. The most well known such scheme is the Refresh Time method analysed by Barndorff-Nielsen, Hansen, Lunde, and Shephard (2011) and subsequently employed by, for example, Christensen, Kinnebrock, and Podolskij (2010) and Aït-Sahalia, Fan, and Xiu (2010). See also the earlier more informal papers by Harris, McMcInish, Shoesmith, and Wood (1995) and Martens (2003).…”