May 14 2009
A must read for AP Macro teachers: Paul Krugman explains why deficit spending during a recession does NOT cause crowding-out
In Krugman’s words:
In effect, we have an incipient excess supply of savings even at a zero interest rate. And that’s our problem.
So what does government borrowing do? It gives some of those excess savings a place to go — and in the process expands overall demand, and hence GDP. It does NOT crowd out private spending, at least not until the excess supply of savings has been sopped up, which is the same thing as saying not until the economy has escaped from the liquidity trap.
In AP Macroeconomics, we teach that deficit-financed government expenditure decreases the supply of loanable funds as savers take their money out of commercial banks and invest in the bond market due to the attractive interest rates on government debt. Less funds available for the private sector drives up interest rates and crowds out private investment.
If the economy is producing close to the full-employment level and interest rates are positive, the decrease in supply of loanable funds can indeed drive up equilibrium interest rates and lead to the “crowding-out” of private investment. Krugman points out in this article that when the economy is at the “zero-bound” (i.e. when nominal interest rates are as low as they can go) and the quantity supplied of savings is still greater than the quantity demanded for investment, the government can effectively borrow from the public, decreasing the supply and correcting the surplus of savings without driving up interest rates in the private market. Put another way, the equilibrium interest rate is below zero, but the “zero-bound” acts as a price floor in the loanable funds market, resulting in a surplus of savings.
Government borrowing crowding out private investment is not something we can worry about during a recession, when low confidence and expectations have driven the supply of savings up and the demand for investment down. Public spending will divert funds from the private sector to the public sector, that’s true. But in today’s case, savings are sitting idle in the private sector, so government borrowing is putting those fund to use when the private sector has failed to do so.
- Why does the supply of loanable funds (S in the graph above) slope upwards? Why does the demand for loanable funds (I in the graph) slope downwards?
- Deficit financed government spending decreases the supply of loanable funds. Why?
- Crowding-out is not the only possible down-side of deficit spending by the government. What are some other long-term effects of governments running budget deficits year after year?
About the author: Jason Welker teaches International Baccalaureate and Advanced Placement Economics at Zurich International School in Switzerland. In addition to publishing various online resources for economics students and teachers, Jason developed the online version of the Economics course for the IB and is has authored two Economics textbooks: Pearson Baccalaureate’s Economics for the IB Diploma and REA’s AP Macroeconomics Crash Course. Jason is a native of the Pacific Northwest of the United States, and is a passionate adventurer, who considers himself a skier / mountain biker who teaches Economics in his free time. He and his wife keep a ski chalet in the mountains of Northern Idaho, which now that they live in the Swiss Alps gets far too little use. Read more posts by this author
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