Hmmm. I was thinking it might be due to the ninja-mined stake that was no longer in circulation. Or that they altered the pay-out formula. 

In the first few days it seemed to me that most people would move to Hive but now it looks like many have either remained or are on both chains. Perhaps as you say, not that many actually moved so there are fewer posts and less money to pay out. I wonder what the actual statistics are?