A WebmasterWorld member asks: how do you find out if you've been smart priced? Do you get notified?
No. It's a "big black box" as someone else says and the amount of money you earned instead is more important.
Other telltale signs:
When you receive only 1 cent to 3 cent clicks over 100's of clicks for ads which sell medium to expensive products or services, you KNOW, you have been smartpriced.
When your income falls suddenly by 50- 60 %, you know you have been smartpriced.
When you can't seem to do anything to increase the EPC, you know you have been smartpriced or capped.
Someone else suggests asking Google themselves. I don't know if that works, however.
If you want more information about it, Google has written about smart pricing in the past.
Forum discussion continues at WebmasterWorld.