Paul A. Volcker in his autobiography “Keeping at it” of 2018, penned together with Christine Harper, valiantly accepted that the risk weighted bank capital requirements he helped to promote, had serious problems. In pages 146-148 he writes:
"The travails of First Pennsylvania and Continental Illinois, the massive threat posed by the Latin American crisis, and the obvious strain on the capital of thrift institutions had an impact on thinking over time, but strong action was competitively (and politically) stalled by the absence of an international consensus.
An approach toward dealing with that problem was taken by the G-10 central banking group meeting under the auspices of the Bank for International Settlements (BIS) headquartered in Basel, Switzerland. A new Basel Committee would assess existing standards and practices in a search for an analytic understanding.
Progress was slow…
The US practice had been to asses capital adequacy by using a simple “leverage ratio”-in other words, the bank’s total assets based compared with the margin of capital available to absorb any losses on those assets. (Historically, before, the 1931 banking collapse, a ten percent ratio was considered normal)
The Europeans, as a group, firmly insisted upon a “risk-based” approach, seemingly more sophisticated because it calculated assets based on how risky they seemed to be. They felt it was common sense that certain kind of assets –certainly including domestic government bonds but also home mortgages and other sovereign debt- shouldn’t require much if any capital. Commercial loans, by contrast, would have strict and high capital requirements, whatever the credit rating might be.
Both approaches could claim to have strengths. Each had weaknesses. How to solve the impasse?
At the end of a European tour in September in 1986, I planned to stop in London for an informal dinner with the Bank of England’s then governor Robin Leigh-Pemberton. In that comfortable setting without a lot of forethought, I suggested to him that if it was necessary to reach agreement, I’d try to sell the risk-based approach to my US colleagues.
As if bureaucrats know better what to do with credit for which repayment they're not personally responsible for than entrepreneurs.
How can one believe that what bankers perceive as risky is more dangerous to bank systems than what bankers perceive as safe?
Should it not be clear that dooms our bank system to especially severe crises, resulting from excessive exposures the what ex ante is perceived as especially safe, but that ex post might not be, against especially little capital?