It is even less clear that there are serious economies of scope in the financial sector – that is, there is little evidence that the financial supermarket view by which the end of Glass-Steagall was justified in the United States leads to more efficient and cheaper provision of financial services.
And although investment banks became commercial banks during the last year, to obtain access to the Fed's facilities, there do not appear to be major economic benefits – and there are certainly potential economic disadvantages – from combining trading activities on a serious scale with normal commercial banking.