The a&l regulatory requirements are certainly not self imposed. And the limits aren’t just in the form of rough ratios. They outline the classes of debt the bal

The a&l regulatory requirements are certainly not self imposed. And the limits aren’t just in the form of rough ratios. They outline the classes of debt the balance sheets can have, how they are accounted for, operational procedures around the balance sheet and extensive reporting requirements. But after 2008 equity holders became more risk adverse so demand tighter deposit to loan ratios. This caused the banks to disengage with lending, one of the things that caused the fed to remove the reserve requirement.