by Pam Martens and Russ Martens, Wall St On Parade:

It took eight years of research to compile a data set of annual balance sheets of more than 11,000 commercial banks dating back to 1870 in 17 advanced economies. And in every country, the study arrived at the same finding: concentrating the banking system in the hands of five or less giant banks leads to financial instability and more severe financial crises. The bank balance sheets of the following countries were examined: Australia, Belgium, Canada, Denmark, Finland, France, Germany, Italy, Japan, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, the United Kingdom, and the United States.