The per-page rate for Kindle Unlimited dropped down to $0.004034 per page for July, 2017.
This downward trend has now continued for several months.
But it’s common for the rate to drop in January for the holiday season, and return upward starting in February.
On the other hand, the KDP Select Global Fund for July, 2017 was $19M, which is a clear million dollars above the $18M payout for June, 2017.
This is part of an upward trend.
So while the per-page rate has dropped recently, overall Amazon KDP is paying even more in combined Kindle Unlimited royalties.
"However, there is another big factor involved. Amazon KDP just introduced KENPC v3.0. If you haven’t already done so, you should check the current KENPC’s of your books. You can check your current KENPC from your KDP bookshelf. Click the Promote and Advertise button next your title (or click the … button to find this option, if necessary), and scroll down.
If your KENPC happens to be longer than it had been, that will help compensate for the lower per-page rate. If your KENPC happens to be shorter now, the lower rate will hurt even more if it continues."
Chris McMullen runs a very good blog for those who can handle more detail on this sort of topic. Here is the link: