Effective Altruism (EA) is a movement trying to invest time and money in causes that do the most possible good per unit investment.
The basic concept behind EA is that you would really struggle to donate 100 times more money to charity than you currently do--but (assuming you are approximately utilitarian), spending a little time researching who to donate to could have an impact on roughly this order of magnitude. And the same argument works for doing good with your career or volunteer hours.
Despite a broad diversity of ideas within the EA community on which areas are most pressing, there are a handful of criteria that are generally agreed make an area potentially impactful to work on (either directly or through donation). These are:...