A number of recent mini-events have conspired to make me think about what I give to charity. One is an email that came round saying that one could have charitable donations directly removed from one's gross pay so that they were tax-efficient. Another was a knock on the door from somebody who was looking for contributors to a Buddhist charity that helps untouchables in India. And a third was a recent post by Ben Green about an Oxford ethical philosopher who urges people to become bankers and give away a substantial proportion of their salary. While looking into the last of these, I saw that the philosopher also stressed that one should choose carefully how to give away the money -- the aim being to do the maximum amount of good, which is a combination of earning as much as possible and maximizing the beneficial effect of what one gives away. I try to do this to some extent (e.g. I don't give to homeless people in the street but do support a charity for the homeless that I presume spends the money more wisely and therefore does more for homeless people). But I haven't been remotely systematic about it. He claimed that the website of his organization offers advice about what charities are particularly efficient, but I couldn't find anything there, so I Googled "cost-effective charities" and came up with this site: http://www.givingwhatwecan.org/resources/charity-comparisons.php

I knew it was the kind of thing I was looking for when I read that one TB charity was less efficient than another because it helped more UK people (who are more expensive to help than people in the developing world, so you end up doing less good for what you give). But what I liked best was that the charity that came top is called Deworm the World. It sounds like a joke but it definitely isn't. Getting rid of nasty worms is cheap (about 20p per treatment in Kenya and 8p in India), but not many people realize how important it is, so they urgently need money. And it does an amazing amount of good. For example, worm-related diseases are a major cause of children missing school, so treating them is an incredibly cost-effective way of increasing school attendance, which of course has numerous knock-on effects. There has been a study of this, of which even the abstract is worth reading: http://www.povertyactionlab.org/evaluation/primary-school-deworming-kenya?pid=21

Ben's post, which links to information about the Oxford philosopher, is here:
https://plus.google.com/112323225026455580520/posts/UWAj7Ei27CT

Maybe he's made a difference to the world by causing me to spend the same amount of money that I would have on charitable giving, but on getting rid of worms instead. Or possibly even better: when the marginal good per extra pound spent is that much higher, it's tempting to give more than I would have.