Does Adsense CTR Affect EPC ?

There seems to be a debate as to whether CTR affects your overall EPC with Adsense. Some people say that having one site in your account that has a low CTR (click-through rate) will cause your earnings to drop across all sites. Others say this isnt a factor.

It's also been said that there are so many factors at play when it comes to your EPC that one person might notice a drastic difference in earnings while another may not.

I was actually inspired to check into this when I read BJ's post titled Hey! Where's Your Adsense? on her Adventures in Net Marketing blog.

A quick search on Google brought up this thread at WebmasterWorld: I just found out: CTR has no effect on EPC. There is some interesting information in that thread...

Even more if you do a search on Google for does ctr affect epc?.

Your thoughts?