What Buffett Wrote About Inflation, 1979–1981

Warren Buffett treated inflation as a tax on capital that could turn a good business into a bad investment for its owners. In the 1981 letter he put it most vividly: "inflation acts as a gigantic corporate tapeworm." The 1979 and 1980 letters build the argument step by step, with numbers.

This post traces what Buffett wrote about inflation across three Berkshire Hathaway shareholder letters, 1979 to 1981, drawn from the 1977–1997 letters in Mímir's library. Each quote links to the original letter.

How does inflation hurt a business's owners? (1979)

In the 1979 letter, Buffett warned that even a 20% return on capital no longer guaranteed a real gain:

"Just as the original 3% savings bond, a 5% passbook savings account or an 8% U.S. Treasury Note have, in turn, been transformed by inflation into financial instruments that chew up, rather than enhance, purchasing power over their investment lives, a business earning 20% on capital can produce a negative real return for its owners under inflationary conditions not much more severe than presently prevail."

He applied it to Berkshire's own shareholders. If Berkshire kept compounding at 20% and the stock followed, "your after-tax purchasing power gain is likely to be very close to zero at a 14% inflation rate."

What is the investor's misery index?

The same letter names the combined burden. Inflation plus the tax an owner pays to move earnings into his own pocket "can be thought of as an “investor’s misery index”." Then the rule:

"When this index exceeds the rate of return earned on equity by the business, the investor's purchasing power (real capital) shrinks even though he consumes nothing at all."

He added: "We have no corporate solution to this problem; high inflation rates will not help us earn higher rates of return on equity."

Why is inflation a tax on capital? (1980)

The 1980 letter opens the argument with a direct claim:

"High rates of inflation create a tax on capital that makes much corporate investment unwise - at least if measured by the criterion of a positive real investment return to owners."

His worked example: with 12% inflation, a business earning 20% on equity and paying it all to owners in the 50% tax bracket "is chewing up their real capital, not enhancing it." Half the 20% goes to income tax, and the remaining 10% leaves owners with only 98% of their starting purchasing power.

What makes inflation worse than an ordinary tax, he argued, is that it has no ceiling: "But the inflation tax is not limited by reported income." Ordinary taxes are levied on nominal income, so the two interact: "Thus you pay income taxes on what would be deficits if returns to stockholders were measured in constant dollars."

His conclusion for taxable individual owners was stark. At the inflation rates of the time, they "should expect no real long-term return from the average American corporation".

Can a business protect itself from inflation?

Rarely, by Buffett's account. "Indexing is the insulation that all seek against inflation", he wrote in 1980, but most corporate capital isn't indexed. Rising dividends don't count if they come from saving more rather than earning more. True indexing has a strict test:

"For capital to be truly indexed, return on equity must rise, i.e., business earnings consistently must increase in proportion to the increase in the price level without any need for the business to add to capital - including working capital - employed."

He added: "Only a few businesses come close to exhibiting this ability. And Berkshire Hathaway isn't one of them."

What is the corporate tapeworm? (1981)

The 1981 letter gives the image the argument is best known for:

"For inflation acts as a gigantic corporate tapeworm. That tapeworm preemptively consumes its requisite daily diet of investment dollars regardless of the health of the host organism."

The mechanism is that more money is "continuously required" for receivables, inventory and fixed assets just to match the previous year's unit volume. Weaker companies suffer most: "The less prosperous the enterprise, the greater the proportion of available sustenance claimed by the tapeworm."

For a business earning 8% or 10% on equity, he wrote, there was often nothing left for expansion, debt reduction or "real" dividends: "The tapeworm of inflation simply cleans the plate." He also warned shareholders: "Beware of “dividends” that can be paid out only if someone promises to replace the capital distributed."

What did inflation mean for bonds?

The 1979 letter turns the same logic on long-term bonds, which Buffett called "the last major fixed price contract of extended duration still regularly initiated in an inflation-ridden world." He wrote that Berkshire had "severe doubts as to whether a very long-term fixed-interest bond, denominated in dollars, remains an appropriate business contract in a world where the value of dollars seems almost certain to shrink by the day."

He allowed that he might be wrong: "Inflation is man-made; perhaps it can be man-mastered." But he closed the section with Polonius, "slightly restated": "Neither a short-term borrower nor a long-term lender be."

The short version

• 1979: A 20% return can still mean a negative real return. The "investor's misery index" (inflation plus tax) decides whether owners gain.
• 1980: Inflation is a tax on capital with no ceiling. Few businesses are truly indexed, and Berkshire wasn't one.
• 1981: Inflation is "a gigantic corporate tapeworm" that eats investment dollars before any are left for owners.

These are reports of what Buffett wrote in specific letters during the high inflation of 1979–1981. They aren't a recommendation about any investment.

To look up what Buffett, Paul Graham, Sam Altman, Marc Andreessen or Naval wrote on your own question, you can ask Mímir. Each answer cites the original letter or essay.