Banks can only expand comfortably in unison when a Central Bank exists, essentially a governmental bank, enjoying a monopoly of government business, and a privileged position imposed by government over the entire banking system. It is only when central banking got established that the banks were able to expand for any length of time and the familiar business cycle got underway in the modern world.
private banks are only able to manipulate money supply and perform credit expansion due to government intervention from central bank (the Fed).
