By James Kwak
Roger Myerson, he of the 2007 Nobel Prize, wrote a glowing review of The Banker’s New Clothes, by Admati and Hellwig, for the Journal of Economic Perspectives a while back. Considering the reviewer, the journal, and the content of the review (which describes the book as “worthy of such global attention as Keynes’s General Theory received in 1936″), it’s about the highest endorsement you can imagine.
Myerson succinctly summarizes Admati and Hellwig’s key arguments, so if you haven’t read the book it’s a decent place to start. To recap, the central argument is that under Modigliani-Miller, the debt-to-equity ratio doesn’t affect the cost of capital and therefore doesn’t affect banks’ willingness to extend credit; the real-world factors that make Modigliani-Miller untrue (deposit insurance, taxes, etc.) rely on a transfer of value from another party that makes society no better off.