Paul Krugman there's huge Excel type data mistake that is bringing the Western economies down into deep depression

Ref: http://economistsview.typepad.com/economistsview/2013/04/paul-krugman-the-excel-depression.html

The regulators of the Basel Committee for Banking Supervision, when designing their risk weighted capital requirements for banks made the outrageous mistake of looking at the specific risks of banks assets, and not at the risk of those assets to the banks, or to the bank system.

That is why they came to assign a whopping 150% risk weight to what is rated below BB-, something so risky that bankers wont even touch it with a ten feet pole; while only a minuscule risk weight of 20% to what is rated AAA and that because of its perceived safety, could cause banks to create such exposures that if ex post the asset turn out riskier, these could bring the whole system down.

That makes banks dangerously lend too much to what is perceived safe and for the economy equally dangerous too little to what is perceived as risky, like SMEs and entrepreneurs. 

The Western world has thrived on risk-taking not risk aversion.

PS. The 0% risk weighing of sovereigns is just as mind-boggling.