On average, effective altruists (n = 412) donated $2503 to charity, and other people (n = 853) donated $523 - obviously a significant result.

There could be some measurement bias here. I was on the fence about whether I should identify myself as an effective altruist, but I had just been reminded of the fact that I hadn't donated any money to charity in the last year, and decided that I probably shouldn't be identifying as an effective altruist myself despite having philosophical agreements with the movement.

1265 people told us how much they give to charity; of those, 450 gave nothing. ... In order to calculate percent donated I divided charity donations by income in the 947 people helpful enough to give me both numbers. Of those 947, 602 donated nothing to charity, and so had a percent donated of 0.

This is blasphemy against Saint Boole.