For example, I'm a medical student in Taiwan. However, I'm confident that going to USA medical school would probably significantly increase my career donations(because the annual salary in Taiwan doctor is:$170k, while it's $400k in USA, even the tuition of USA med school is $400k more than Taiwan, the career earning is definitely higher). Also, even if I study medicine in Taiwan, it's better for me to become a private clinic owner, which needs a significant amount of money. If I got these loaning, after I return all the loanings, in expected value I could donate $250-500k more in my lifetime.
It's very hard to get loaning on the two above mentioned situations(especially, it's impossible to get loaning as an international student in USA).
I could understand EA donors can't fund any researcher because the funding is limited. However, loaning is different, it would increase the funding in long-term.
Therefore, I think Coefficient giving and other EA majors should do EA loaning, it would significantly be beneficial to relieve the funding gap in EA.

Interesting suggestion! I think the example you outline makes sense. I'd guess part of why you don't see this kind of thing in EA might include:
Anyway, just some quick thoughts, very open to counter takes and thank you for suggesting this idea! I do think there is a good place for some smart finance type stuff in EA for sure, such as loans for social enterprises to kick off, or other clever things like advance market commitments.
Interesting idea, but I'd advise you to map it out more. This post seems fairly low effort, and you may get more engagement if you fleshed it out a bit.
No, funders can get even more money for effective philanthropy by investing in AI.