The problem is we're both arguing theories, and I'm willing to concede that but perhaps you aren't.
We have a single fact - abortions in NYC decreased by a more significant percentage than nationally during Rudy Giuliani's term as mayor.
The theories are did Rudy do anything that contributed to that or did it somehow miraculously happen without him doing anything.
Considering the large drop in crime and general "cleaning up" of the city, I'd say his policies played a fairly good-sized role. Perhaps they didn't directly refer to abortion, but an improvement in vice crime, druggies, etc., etc., will most likely also lead to decreased abortion.
Whatever - the FACT is that abortions decreased more under Rudy than elsewhere.
Now it's your turn to provide a source that PROVES beyond a reasonable doubt that it would have happened even if Dinkins were still mayor.
Still waiting for the cite on that one.