“[T]here is only one best charity: the one that helps the most people the greatest amount per dollar. This is vague, and it is up to you to decide whether a charity that raises forty children’s marks by one letter grade for $100 helps people more or less than one that prevents one fatal case of tuberculosis per $100 or one that saves twenty acres of rainforest per $100. But you cannot abdicate the decision, or you risk ending up like the 11,000 people who accidentally decided that a pretty picture was worth more than a thousand people’s lives.”

— Scott Alexander, Efficient charity: do unto others…