WELCOME BACK, CARTER: A New Era of Stagflation?

The most likely outcome in my view is that the biggest US consumer stimulus in history will produce sustained inflation in excess of 5 percent a year. Falling real wages and shrinking profit margins will continue to depress output, and the US economy will enter a period of stagflation something like the late 1970s. At some point, the United States Treasury will find itself unable to borrow the equivalent of 10% of GDP per year, at least not at negative real interest rates. As long as investors are willing to pay the Treasury to hold their money for them, the US government can sustain arbitrarily large deficits. That is the brunt of so-called Modern Monetary Theory. But the Herb Stein principle applies: Whatever can’t go on forever, won’t. The creditors of the United States will not accept negative returns on an ever-expanding mountain of US debt indefinitely. At some point, perhaps not long from now, the US will face sharply higher interest rates and the type of budgetary constraints that were typical of profligate Third World borrowers.

Related: Stall: Economy falls to 2% GDP growth in Q3