Banking shouldn't have a reserve ratio. Rather, banks should have to show that they have a claim to each dollar they have loaned out for the period they have loaned it. This means they have to lend short and borrow long.
The insight here is that the problem with banking since time immemorial is rooted in a lie: multiple people have claims of ownership on the same dollar at the same point in time. Rather than using a reserve ratio to paper over this lie, we should simply ban lying. Banks offer CD like products that lock up money for a certain amount of time, and that money can be loaned out for a period less than or equal to that amount of time.
Practically this would imply a balance curve for a bank at time T, B(T) and their loan curve L(T) would need <= B(T) for all T. You would be able to see if a bank was in trouble way out in advance.
Again, this would mean that banks would not need a reserve ratio. A dollar could theoretically be lended out an infinite number of times, so long as the dollar was put back into the bank at a term longer than the next demanded loan.
Finally, I would make banks a special entity partnership, where partners were held liable for losses up to a certain % of revenues.
