You don't ban making loans! You ban fractional reserve banking - the act of issuing currency not backed 1:1 by central bank money.
All it takes to stop boom/bust is full reserve banking and abolition of central bankers. Very simple, technically. After that to get yield on savings, people must invest in funds and be exposed to their relative lack of liquidity. Good bankers can keep things relatively liquid anyway, at least when times are stable, but you'd still have to wait to get your money back if you wanted out of investment funds. The underlying mechanics of finance are exposed: loans still occur, but investors see that their money is gone from their current accounts until the fund reaches maturity.
Now, will the citizens or politicians tolerate the long sucking sound as all the unstable credit is withdrawn from the economy? No, probably not. It's politically hard, not technically hard.
All it takes to stop boom/bust is full reserve banking and abolition of central bankers. Very simple, technically. After that to get yield on savings, people must invest in funds and be exposed to their relative lack of liquidity. Good bankers can keep things relatively liquid anyway, at least when times are stable, but you'd still have to wait to get your money back if you wanted out of investment funds. The underlying mechanics of finance are exposed: loans still occur, but investors see that their money is gone from their current accounts until the fund reaches maturity.
Now, will the citizens or politicians tolerate the long sucking sound as all the unstable credit is withdrawn from the economy? No, probably not. It's politically hard, not technically hard.