Wills are for when you die. Living wills guide your affairs when you lose the capacity to act. We’re all mortal and fragile – not just people, but firms and banks, too. The Dodd-Frank Act of 2010 requires systemic intermediaries (and many others) to create “living wills” to guide their orderly resolution in bad times.

In August, these Dodd-Frank living wills made front-page business news when the FDIC and the Fed rejected those submitted by the biggest banks as inadequate. That should come as no surprise. In their current form, we doubt that living wills would do much to secure financial stability...