In the past several decades banks have grown relentlessly. Many have become very large—both in absolute terms and relative to their economies. During the recent financial crisis it became apparent that large bank size can imply large risks to a country’s public finances. In Iceland failures of large banks in 2008 triggered a national bankruptcy. In Ireland the distress of large banks forced the country to seek financial assistance from the European Union and International Monetary Fund in 2010.
An obvious solution to the public finance risks posed by large banks is to force them to downsize or split up. In the aftermath of the EU bailout Ireland will probably be required to considerably downsize its banks, reflecting its relatively small national economy. In the United Kingdom the Bank of England has been active in a debate on whether major U.K. banks need to be split up to reduce risks to the British treasury. In the United States the Wall Street Reform and Consumer Protection Act (or Dodd-Frank Act) passed in July 2010 prohibits bank mergers that result in a bank with total liabilities exceeding 10 percent of the aggregate consolidated liabilities of all financial companies, to prevent the emergence of an oversized bank.
So public finance risks of systemically large banks are obvious. But what are some of the other costs (and benefits) associated with bank size? This is the question Harry Huizinga and I try to address in a recent paper. Specifically, we look at how large banks are different in three key areas: