by Yi Wen, Assistant Vice President and Economist, and Maria A. Arias, Research Associate – Federal Reserve Bank of St. Louis
Inflation is typically described as a persistent increase in the general price level, such as in the consumer price index. One of the most important theories to explain inflation is the monetarist view that, according to Milton Friedman, “Inflation is always and everywhere a monetary phenomenon.”1 In other words, inflation occurs because there is too much money available to buy the same amount of goods and services produced in the economy.
This view can also be represented by the so-called “quantity theory of money,” which relates the general price level, the total goods and services produced in a given period, the total money supply and the speed (velocity) at which money circulates in the economy in facilitating transactions in the following equation:
MV = PQ
In this equation:
- M stands for money.
- V stands for the velocity of money (or the rate at which people spend money).
- P stands for the general price level.
- Q stands for the quantity of goods and services produced.
Based on this equation, holding the money velocity constant, if the money supply (M) increases at a faster rate than real economic output (Q), the price level (P) must increase to make up the difference. According to this view, inflation in the U.S. should have been about 31 percent per year between 2008 and 2013, when the money supply grew at an average pace of 33 percent per year and output grew at an average pace just below 2 percent. Why, then, has inflation remained persistently low (below 2 percent) during this period?
The issue has to do with the velocity of money, which has never been constant, as can be seen in the figure below . If for some reason the money velocity declines rapidly during an expansionary monetary policy period, it can offset the increase in money supply and even lead to deflation instead of inflation.
The velocity of money can be calculated as the ratio of nominal gross domestic product (GDP) to the money supply (V=PQ/M), which can be used to gauge the economy’s strength or people’s willingness to spend money. When there are more transactions being made throughout the economy, velocity increases, and the economy is likely to expand. The opposite is also true: Money velocity decreases when fewer transactions are being made; therefore the economy is likely to shrink.
During the first and second quarters of 2014, the velocity of the monetary base2 was at 4.4, its slowest pace on record. This means that every dollar in the monetary base was spent only 4.4 times in the economy during the past year, down from 17.2 just prior to the recession. This implies that the unprecedented monetary base increase driven by the Fed’s large money injections through its large-scale asset purchase programs has failed to cause at least a one-for-one proportional increase in nominal GDP. Thus, it is precisely the sharp decline in velocity that has offset the sharp increase in money supply, leading to the almost no change in nominal GDP (either P or Q).
So why did the monetary base increase not cause a proportionate increase in either the general price level or GDP? The answer lies in the private sector’s dramatic increase in their willingness to hoard money instead of spend it. Such an unprecedented increase in money demand has slowed down the velocity of money, as the figure below shows.
And why then would people suddenly decide to hoard money instead of spend it? A possible answer lies in the combination of two issues:
- A glooming economy after the financial crisis
- The dramatic decrease in interest rates that has forced investors to readjust their portfolios toward liquid money and away from interest-bearing assets such as government bonds
In this regard, the unconventional monetary policy has reinforced the recession by stimulating the private sector’s money demand through pursuing an excessively low interest rate policy (i.e., the zero-interest rate policy).3
Indeed, during the prerecession period, for every 1 percentage point decrease in 10-year Treasury note interest rates, the velocity of the monetary base decreased 0.17 points, based on a linear regression model of the velocity onto interest rates. Since 10-year interest rates declined by about 0.5 percentage points between 2008 and 2013, the velocity of the monetary base should have decreased by about 0.085 points. But the actual velocity has gone down by 5.85 points, 69 times larger than predicted. This happened because the nominal interest rate on short-term bonds has declined essentially to zero, and, in this case, the best form of risk-free liquid asset is no longer the short-term government bonds, but money.
Notes and References
1 Friedman, Milton. “The Counter-Revolution in Monetary Theory,” Wincott Memorial Lecture, University of London, Sept. 16, 1970.
2 The monetary base includes notes and coins in circulation as well as bank reserves.
3 See our article “The Liquidity Trap: An Alternative Explanation for Today’s Low Inflation” in The Regional Economist for a more detailed explanation.
- Regional Economist: The Liquidity Trap: An Alternative Explanation for Today’s Low Inflation
- On the Economy: Forecasting National Inflation Rates
- On the Economy: Recent ECB Policy and Inflation Expectations