The Law of Comparative Advantage is a relevant concept here, because whatever you end up doing would have been done by someone else if you had made a different choice.
I believe that if I donate to charity, more will be donated to charity. If I do research in a field, more research will get done in that field. If I start a company, more companies will get started. (All of this in in expectation). This holds even more true for a particularly charity, a particular research program I consider important, or a particular need I think needs to be filled.
don't forget to do something you'll enjoy
I'm not too worried about this. I enjoy both thinking and deliberating in a very broad sense, and I could direct the time I spend on both in pretty arbitrary directions before it became unfun. My plan is to find out what would be best, and then think about how to perturb it to keep me happy enough to remain productive.
I believe that if I donate to charity, more will be donated to charity. If I do research in a field, more research will get done in that field. If I start a company, more companies will get started.
I agree on charity, but what if the funding for research in a field is limited, and there is someone who is better at doing research than you are, but worse at doing job interviews, so by deciding to go into that field, you take their place? Similarly for starting companies, if there's a profitable niche, it will be filled by someone sooner or later, unless ...
I have been having some difficulty deciding what to do with my life. I'm not really ashamed or surprised, because the problem seems extremely difficult and worth getting right. I still don't really know. Here are some of my options, though I wouldn't be surprised if what I end up doing is not on the list. I thought I would share to elicit advice, to give some context to some of my recent remarks, and maybe to provide comparison for people in similar situations.
1. Research
I could do research in a university, or in a private research lab. Many fields have at least a few questions that seem important and interesting.
A. Theoretical Computer Science. I could work on collaborative learning, recommendation and reputation systems, distributed protocols, or anything else that might assist collaboration in the future.
B. AI / Computational Cognitive Neuroscience. I could work on algorithms for inference and planning, to increase the probability that we develop comprehensible or human-like AI before something horrible happens (like developing incomprehensible strong AI).
C. Neuroscience. I know almost nothing about this field, but technology for measuring and interfacing with the brain appears to be important and developing rapidly. I don't know how hard it would be to start working in the field, but I suspect that the connection to computer science is strong enough at MIT that it wouldn't be impossible.
2. Start a company
This seems way harder, but I am sufficiently arrogant and risk-neutral that I consider it a reasonable option. In particular, this is what I would do if I decided that making money as efficiently as possible and giving it away
A. Tech company. If I had to guess based on the currently available evidence, I would guess that this is the way to maximize my expected earnings.
B. Online Education. I would like to take a shot at designing materials for online education of smart, significantly underserved, high school students.
3. Cooperate with Other Rationalists
A. Work for a rational charity. Self-explanatory. Probably worse than earning a lot of money and giving away.
B. Start a rational charity. Probably worse than supporting an existing charity.
C. Work for a rational start-up. Can't really arrange this one; but optimistically it could happen if you were prepared (someone else does 2).
4. Be a Hobbyist
I could also simply try and earn a living as quickly as possible (rather than making as much excess as possible, or having a more structured way of doing good) and do work on the side. I don't think this is a good idea.