My understanding is that you're never guaranteed RC funding and, also, the cost of doing so is that you have to do the research particular to that grant; so you

My understanding is that you're never guaranteed RC funding and, also, the cost of doing so is that you have to do the research particular to that grant; so you've either got to hope for something related to your field, or go for something close enough to keep you interested. I've heard (sorry: no citations) that here in the UK, around 60% of PhDs are actually self-funded -- to pay the tuition fees, mostly -- and while I don't know the breakdown, that also includes research in the sciences. The upside of self-funding is that you're free to research what you want, within reason (i.e., it's actually worthwhile, the university agrees and you can find a supervisor, etc.)