We do have some ongoing research, the problem is we have no funding or staff to work it for publication.
So far, there have been no significant variation of what we found and published. Except, there is less giving in American churches, from 2006 to present, due to the economy and loss of jobs and a decrease of income. That is the big variance now and we have not seen any improvement in the last several months, contrary to what has been reported in the media; rather, a significant decrease in giving across the board.
The key reason is less about money, and more about the fear of losing what one already has or can have.
Thus, many Christians are not giving because of fear and not realizing the providence of God or being grateful for Who and What He has done.