Professor Mervyn King, our friend, NYU Stern colleague and the former Governor of the Bank of England, has written a wonderfully insightful and thought-provoking new book, The End of Alchemy. His goal is not just to explain the sources of the 2007-09 crisis, but to provide a template for financial reform that would reduce the frequency and severity of future crises. In the end, Professor King proposes a radical structural change intended to make banking safe while preserving the intermediation function that is critical to modern economies.

The alchemy to which Professor King refers in his book’s title is banks’ traditional function of transforming high-risk, illiquid and long-maturity assets into low-risk, liquid and short-term liabilities. But, in the presence of limited liability for the banks’ owners and the government safety net (in the form of deposit insurance and the lender of last resort that remove both solvency and liquidity risk for the depositors), banks’ incentive is to transform too much. Holding assets that are overly risky, insufficiently liquid and too long-term makes banks fragile and run-prone, providing fodder for systemic crises....