Should you donate to a disaster relief fund following a traumatic earthquake or is eradicating a global disease a better use of your money? Do you introduce micro-financing to an underdeveloped market or pump cash into reducing rates of youth incarceration in the US? Or do you look solely to the future and devote your spare change to mitigating against the risk of a potentially earth-destroying event such as an asteroid crash, climate change or rogue artificial intelligence?