The stuff from Varouflakis
The stuff from Varouflakis confirms the point that the discussion amongst bourgeois economists, conventional and unconventional, is not so much about what banks can and cannot do or should or should not be allowed to do as about which policy to pursue to try prevent bank lending getting out of hand in a boom.The theories they have developed are theories tailored to back up their preferred policy. Pretty academic really as none of them are going to work as "excessive" bank lending in a boom is neither the cause of the boom nor the reason why it will eventually end. It is, rather, a reflection of the boom. Booms and slumps are not cause by monetary movements but by movements in the real, productive economy. It is true, though, that mistaken monetary policies can make things worse. For instance, what Positive Money propose: not allowing banks to lend from customers' current accounts would restrict the flow of credit to productive industry and so hold back the accumulation of capital.