Why do gentiles give so little?

David Aaronovitch has a must-read column in this week's Jewish Chronicle. Unfortunately it's not on line. Here's his main, provocative but wise, point:

How does it come about that Lord Levy was succeeded by Mr Mendelsohn, that Sir Ronald Cohen has been such a big supporter of Gordon Brown's and that British political parties would go to the wall if it weren't for the fundtaising skills of members of the [Jewish] community?

...If the Jewish presence in charitable work and fundraising is disproportionately large, then someone else's contribution must - logically - be disproportionately small. If Jews give a lot, isn't this a way of saying that some people give very little?

...So here's my reworking of the big question: not, why are Jews always involved in donating money, but rather, why are gentiles so mean?