This was interesting: ...the question is why bankers bought those triple-A mortgage-backed securities, and the answer may well lie in the regulations promulgat

This was interesting: ...the question is why bankers bought those triple-A mortgage-backed securities, and the answer may well lie in the regulations promulgated by government officials.[6] Had bankers been looking for the safety connoted by triple-A ratings, they could have bought Treasurys, which were even safer. If they were looking for yield, they could have bought double-A or lower-rated bonds. And why mortgage-backed bonds? The answer seems to be an obscure rule enacted by the Fed, the FDIC, the Office of the Comptroller of the Currency, and the Office of Thrift Supervision in 2001: the Recourse Rule, an amendment to the Basel I accord that governed banks' capital minima. Under the Recourse Rule, an AA- or AAA-rated asset-backed security, such as a mortgage-backed bond, received a 20-percent risk weight, compared to a zero risk weight for cash and a 50-percent risk weight for an individual (unsecuritized) mortgage. This meant that commercial banks could issue mortgages regardless of how sound the borrowers were sell them to investment banks to be securitized, and buy them back as part of a mortgage-backed security, in the process freeing up 60 percent of the capital they would have had to hold against individual mortgages. Capital held by a bank is capital not lent out at interest; by reducing their capital holdings, banks could increase their profitability. Fascinating read.