THE WORLD NEEDS AMERICA TO HAVE A MORE GENEROUS WELFARE STATE:

[Brad DeLong, from the University of California at Berkeley], who also blogs for the Washington Center for Equitable Growth bases his argument on a simple observation.

The interest rate that rich countries with super-safe debt (in the case of the eurozone, that means Germany but not Spain) pay is astonishingly low: lower than the growth rate of nominal gross domestic product (that is, GDP before subtracting inflation). In the U.S., the Treasury yield has gone from roughly equal to growth in nominal GDP in 2005 to 3 percentage points lower today.

By Mr. DeLong's reckoning, this means those countries are borrowing too little. Bond yields and prices move in opposite directions, so low government bond yields equate to very valuable government bonds. Mr. DeLong asks, "Isn't the point of the market economy to make things that are valuable?" Since the debt of rich countries is "very cheap to make... shouldn't we be making more of it?"

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