[zeep]

This is true for most charities... you are probably better off helping someone you know personally even if it's not tax deductible...

[jacalata]

I don't think this is intrinsically true - a lot of people just don't personally know anyone who desperately needs help. Is it really overall better to be 100% efficient at getting a rich private school a new telescope instead of being 50% efficient at getting people with no safe drinking water a means of access/production of safe drinking water?

[skybrian]

If getting maximum impact is your main concern, I'd go with GiveWell's recommendations:

http://www.givewell.org/charities/top-charities