Observing that, over the past half century, consumer spending has amounted to about 90 percent of income, it might appear that income is largely sufficient to explain consumption. However, econometric evidence suggests that such numbers may be deceptive.
Smart regulation ensures that financial institutions can still pursue their business, but that they are appropriately protected against the biggest risks. This then safeguards the economy, consumers and the financial system itself against turbulence. Therefore, the reason we can't give banks and savings banks full rein is because of the important part they play in the economic cycle.