I know in my cong, I assist with the contribution boxes occasionally, and I have seen a huge drop in the last few years. Years ago it wasn't uncommon to see $500+ in the boxes. Now we rarely break $75. No "big contributors" have left the hall either; it's the same ol' people. They just aren't contributing anymore.
It all goes to show, people would rather do things because they want to, rather than being told to.
"The branch" got it's revenge though. They seized our congregation's savings (I'm sorry, I mean "asked that it be contributed to the worldwide work"), merged 6 congregations and emptied out 3 kingdom halls that will soon be sold. So they'll get that money one way or another.