The lower average rating and longer maturity range of the Vanguard index give the fund a higher yield, risk and volatility.

FORBES: Better Bonding

Debt with a maturity range of one to 10 years has zoomed from 42% in 2001 to more than 53% last year.

FORBES: Fact and Comment

The hope is that by extending the maturity of central-bank money, broadening the range of collateral against which banks can borrow and shifting from direct lending to an auction, the central bankers will bring down spreads in the one- and three-month money markets.

ECONOMIST: A collaboration over the credit crisis