This is a really tricky issue; there are lots of competing considerations either way. (e.g. the return you get from your money; but your donated money also generates a 'social return', which can be much higher than what you get in a bank. And you'll learn more about how to do good later on; but the world is also getting richer so there might be fewer outstanding opportunities in the future. Etc etc.) There's a summary of blogposts on the topic here: http://www.effective-altruism.com/ea/4e/giving_now_vs_later_...