I saw dramatically decrease in clicks and CTR too at my blog once Google announce their new improvemet? have you experienced this?
Only thing that's happened to me is a little bit of a SERP fluctuation with a couple of my sites. CTR is still normal; earnings are the same.
good luck to who has same CTR and ECPM but poor me as it decreased dramatically these days, hope nothing worse?
On one site my earnings have nearly halved since the 15th, this is a large site with previously consistent earnings... im seriously considering my options here.