Can the Fed keep a lid on inflation?

Jeremy Siegel, Wharton finance professor, says the Fed has poured a tremendous amount of money into the economy in response to the pandemic, which will eventually cause higher inflation. David Rosenberg of Rosenberg Research argues that velocity of money is declining and the US economy has a large output gap so inflation is unlikely to materialize.

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Both are right, just in different time frames.

Putting the cart before the horse

The velocity of money is simply the ratio of GDP to the money supply. Fluctuations in the velocity of money have more to do with fluctuations in GDP than in the money supply. If GDP recovers, so will the velocity of money. Equating velocity of money with inflation is putting the cart before the horse. Contractions in GDP coincide with low/negative inflation while rapid expansions in GDP are normally accompanied, after a lag, by rising inflation.


Money supply and interest rates

Inflation is likely to rise when consumption grows at a faster rate than output. Prices rise when supply is scarce — when we consume more than we produce. Interest rates play a key role in this.

Low interest rates mean cheap credit, making it easy for people to borrow and consume more than they earn. Low rates also boost the stock market, raising corporate earnings because of lower interest costs, but most importantly, raising earnings multiples as the cost of capital falls. Speculators also take advantage of low interest rates to leverage their investments, driving up prices.

S&P 500

In the housing market, prices rise as cheap mortgage finance attracts buyers, pushing up demand and facilitating greater leverage.

Housing: Building Starts & Permits

Wealth effect

Higher stock and house prices create a wealth effect. Consumers are more ready to borrow and spend when they feel wealthier.

High interest rates, on the other hand, have the exact opposite effect. Credit is expensive and consumption falls. Speculation fades as stock earnings multiples fall and housing buyers are scarce.

Money supply is only a factor in inflation to the extent that it affects interest rates. There is also a lag between lower interest rates and rising consumption. It takes time for consumers and investors to rebuild confidence after an economic contraction.

The role of the Fed

Fed Chairman, William McChesney Martin, described the role of the Federal Reserve as:

“… take away the punch bowl just as the party gets going.”

In other words, to raise interest rates just as the economic recovery starts to build up steam — to avoid a build up of inflationary pressures.

The Fed’s mandate is to maintain stable prices but there are times, like the present, when their hands are tied.

Federal government debt is currently above 120% of GDP.

Federal Debt/GDP

GDP is likely to rise as the economy recovers but so is federal debt as the government injects more stimulus and embarks on an infrastructure program to lift the economy.

With federal debt at record levels of GDP, raising interest rates could blow the federal deficit wide open as the cost of servicing Treasury debt threatens to overtake tax revenues.


Inflation is likely to remain low until GDP recovers. But the need to maintain low interest rates — to support Treasury markets and keep a lid on the federal deficit — will then hamper the Fed’s ability to contain a buildup of inflationary pressure.