What caused inflation after 2020?
The actual drivers, weighted.
Most policy debates treat inflation as a single phenomenon. It is not. Different causes require different responses, and the CPI only captures part of the picture. The four mechanisms matter because the Fed's tools work on one of them and mostly cannot touch the others.
Post-2020 inflation had three drivers: supply-chain shocks (container costs up 10×, semiconductor shortage), $5T+ in fiscal stimulus flooding demand, and M2 money-supply expansion of 41%. The weight: roughly 40% supply, 40% demand/fiscal, 20% monetary, but they compounded, not isolated.
- Supply-chain: Shanghai-to-LA container rates went from ~$2,500 to $25,000+. Semiconductor lead times doubled.
- Fiscal demand: $5T+ in stimulus checks, PPP, expanded unemployment, cash directly into consumer spending.
- Monetary: M2 grew 41% in 25 months. The Fed's balance sheet peaked at $8.9T. Both were unprecedented outside wartime.
- Energy: oil went negative in April 2020, then surged above $120 by mid-2022. Gasoline drove ~30% of headline CPI in 2022.
- CPI peaked at 9.1% (June 2022), then fell to ~3% by late 2023 as supply chains normalized and QT began.
Demand-pull is "too much money chasing too few goods." Cost-push is a supply shock. Monetary inflation is new currency diluting the existing stock. Asset-price inflation is the Cantillon Effect, new money lifting stocks and housing before reaching consumer prices. The CPI captures demand-pull and some of the others in consumer-basket form, but misses monetary and asset-price inflation almost entirely. That is why official CPI can read 3% while your real cost of living is rising at 7% and the stock market is up 20%.
Section 1 · Why this distinction matters
Policy responses depend on which type of inflation is driving the numbers. Raising interest rates cools demand, which works for demand-pull inflation. It does nothing about an oil supply shock. It does nothing about money already printed and circulating. And it does little about asset-price inflation that is compounding in 401(k)s and home equity while wages lag.
When a politician says "inflation is under control" because CPI fell from 9% to 3%, that is one measurement of one kind of inflation. The cumulative damage from the 2020–2024 monetary expansion is permanent, CPI falling back to 3% does not unwind the 40% M2 expansion[1] that caused the run-up.
Section 2 · Type 1: Demand-pull inflation
Too much money chasing too few goods. Buyers want to spend more than producers can supply, and producers respond by raising prices.
2021–2022. Stimulus checks and expanded unemployment benefits put trillions of dollars into household accounts. At the same time, pandemic supply-chain disruptions reduced the availability of goods (semiconductors, used cars, shipping capacity). The result was a textbook demand-pull surge: plenty of cash, limited goods, fast price increases. CPI peaked at 9.1% in June 2022[2].
The Fed's tool: raise interest rates to cool demand. This is the one type of inflation the Fed's playbook addresses. Higher rates make borrowing more expensive, which slows spending, which lets supply catch up. It is not free, it causes recessions, but it works.
Section 3 · Type 2: Cost-push inflation
A supply shock drives up the cost of producing everything else. Energy, labor, raw materials, when the cost of inputs rises, the cost of outputs rises downstream.
1973 OPEC oil embargo. Crude quadrupled in price[3]. Everything that uses energy (which is everything) got more expensive. This was not caused by too much money. It was caused by oil exporters cutting supply.
The Fed's tool: mostly useless. Raising rates does not create more oil. You get stagflation, inflation plus recession simultaneously, because the supply shock hits output and prices at the same time.
The 1970s stagflation era is the historical warning. The Fed's attempts to fight cost-push inflation with rate hikes produced multiple recessions without solving the underlying energy problem. It took Volcker's willingness to crush the economy with 20% rates to break the inflation expectations that had embedded, plus the eventual resolution of the energy supply shock itself.
Section 4 · Type 3: Monetary inflation
Expansion of the money supply causes all prices to rise over time. This is Milton Friedman's definition: "Inflation is always and everywhere a monetary phenomenon."
M2 money supply grew from $15.4T in February 2020 to $21.7T by April 2022, roughly 41% in 25 months[1]. That is the monetary expansion. Everything else, supply chain disruptions, stimulus, Fed policy, fed into it. The monetary expansion is not fully captured by CPI because CPI measures a basket of consumer prices, not the money stock.
Monetary inflation works with a lag. New money takes time to circulate, time to bid up prices, time to show up in the basket BLS measures. Some of it never shows up in CPI at all because it goes into assets (see Type 4). But the purchasing power of each dollar, over long horizons, tracks the money supply more closely than any consumer-basket index.
The Fed is the cause here. Monetary inflation is the type of inflation where "the Fed" is not a tool but the source. Quantitative easing, large-scale asset purchases, and reserve expansion all increase M2 directly or indirectly. There is no rate-hike fix for money already created and circulating.
Section 5 · Type 4: Asset-price inflation
New money flows into assets (stocks, real estate, Bitcoin, art) before it reaches consumer goods. This is the Cantillon Effect in action: whoever receives the new money first can buy assets at pre-inflation prices and sell them at post-inflation prices.
Between March 2020 and early 2022, the S&P 500 rose roughly 100%[4] and the Case-Shiller National Home Price Index rose about 40%[5]. Over the same period, official CPI rose roughly 15% cumulative. Asset owners saw their net worth balloon while wage earners saw roughly flat real wages. That gap, the difference between asset-price inflation and consumer-price inflation, is the mechanism behind widening wealth inequality since 1971.
The wage side of this divergence is reinforced by a labor-market feature called sticky wages: nominal pay adjusts downward slowly or not at all, even when conditions warrant it. When inflation runs hotter than wage growth, employers do not formally cut nominal salaries; the inflation gap quietly cuts real wages instead verify×DON'T TRUST, VERIFYClaim: Nominal wages exhibit downward rigidity ("sticky wages"); inflation reduces real wages without explicit nominal cuts.Verify at: Akerlof, Dickens, and Perry (1996), "The Macroeconomics of Low Inflation," Brookings Papers on Economic Activity ↗Akerlof, Dickens, and Perry document downward nominal wage rigidity in US data. The mechanism is well-established in labor economics.. From the worker's perspective the effect is the same as a pay cut, but framing it as inflation rather than as a salary reduction is part of why the transfer is politically tolerable.
The CPI does not measure asset prices. By construction, the CPI basket is consumer goods and services, groceries, housing costs (imperfectly, via owner's equivalent rent), energy, apparel, medical care. Stock prices, home prices (as a capital asset), and Bitcoin are excluded. This is the technically correct design choice for what CPI is supposed to measure. It also means official inflation numbers miss the channel through which most monetary expansion actually expresses itself.
See The Cantillon Effect: Who Gets New Money First for the 300-year-old framework that explains why new money moves through assets before goods.
Section 6 · Why the CPI understates real inflation
The Consumer Price Index is a useful benchmark. It is not a complete measurement of purchasing-power loss. Four methodological choices limit what it captures:
- Hedonic adjustments. If a TV's features improve, the BLS adjusts the price downward to reflect "quality-adjusted" cost, even if the sticker price went up. Defensible in theory, but it means you can see the sticker price rise while CPI shows it as flat or declining.
- Substitution bias. When beef gets expensive, the BLS assumes consumers switch to chicken and adjusts the basket. This tracks what people actually buy, but it ignores the quality-of-life loss from being priced out of beef.
- Owner's equivalent rent (OER). Instead of measuring home prices directly, CPI uses a survey asking homeowners what they would charge to rent their own home. OER lags actual rent and home-price changes by 12–18 months and does not capture capital-asset appreciation at all[6].
- Core CPI excludes food and energy. "Core" CPI is the headline measure economists watch because food and energy are volatile. But those are also the categories that affect household budgets most directly and that tend to track monetary expansion most closely.
- Shrinkflation and quality degradation. Package-size reductions and quality downgrades are supposed to be caught by CPI adjustments but the corrections lag and quality changes are modeled rather than measured. See Shrinkflation for the full breakdown of what CPI misses at the grocery shelf.
The full downstream effect of under-measured inflation, how it cascades into housing, family formation, government expansion, and political instability, is documented on Downstream Consequences.
Section 7 · Why the Fed targets 2% inflation (and why that's not crazy)
The Federal Reserve's 2% inflation target is not arbitrary and not malicious. The strongest version of the pro-central-bank case deserves a hearing on its own terms before anyone rebuts it. There are real reasons mainstream economists settled on this number.
When prices are falling, people delay purchases. If a laptop will be 5% cheaper next month, you wait. That delay reduces current demand, which reduces production, which causes layoffs, which reduces demand further. It feeds on itself. The Great Depression was partly a deflation spiral; U.S. consumer prices fell roughly 24% between 1929 and 1933[8]. Japan has spent three decades fighting its own deflationary pull with limited success. Central banks learned from both episodes. A small positive inflation rate keeps the wheels turning.
If the inflation target were 0%, a recession could require the Fed to cut real rates negative. But the nominal federal funds rate cannot easily go below zero without extraordinary measures (negative-rate policy, as tried in Japan and the ECB, has mixed results and political costs). A 2% inflation cushion gives the Fed room to maneuver: cutting a nominal rate from 4% to 1% during a downturn is a meaningful tool. Academic work going back to Bernanke, Reinhart, and Sack (2004) formalized this argument[9].
Almost all money in the modern economy is created as debt (see credit creation). A small amount of inflation makes that debt easier to service because the real value of what you owe shrinks slightly each year. For governments running deficits, this is obviously convenient. For a homeowner with a 30-year fixed-rate mortgage, it is a genuine benefit: wages rise with inflation, the mortgage payment does not. The 2% target is not purely a government-friendly trick; millions of ordinary borrowers benefit from it.
The 2% target is defensible in theory. The problem is not the target; it is execution. M2 grew about 41% in 25 months from 2020 to 2022, not 2% annually[1]. The Fed's balance sheet went from roughly $900B pre-2008 to a peak near $8.97T in April 2022[10]. Headline CPI peaked at 9.1% in June 2022[2], not 2%. And there is no mechanism to claw back purchasing power already lost. Prices that rose do not fall back when CPI returns to target; they just stop rising as fast.
Even the target, hit perfectly, compounds. 2% per year for 50 years erodes purchasing power by about 64% don't trust, verify×DON'T TRUST, VERIFYClaim: 2% compounded over 50 years = ~64% purchasing-power loss.Verify at: BLS inflation calculator ↗Math: 1 − 1/(1.02^50) = 0.6285. The BLS calculator shows cumulative CPI effects on historical data.. The math: 1 − 1/(1.02^50) ≈ 63%. That is the "success case." The actual post-1971 dollar has lost roughly 87% of its purchasing power, closer to 4% annualized. Even theoretical success is not wealth preservation.
Section 8 · What this means for Bitcoin
Bitcoin's fixed supply removes the question of whether the target gets hit. There is no target. There is no discretion. 21 million coins, issued on a schedule written into the protocol in 2009. Whether the Fed succeeds or fails at 2% does not affect what a satoshi represents.
A fixed-supply asset is neutral for which type of inflation is happening. All four types erode the purchasing power of unbacked fiat over long horizons. None of them can inflate Bitcoin's supply.
Whether inflation shows up in consumer prices (Type 1 or 2), in monetary aggregates (Type 3), or in asset prices (Type 4), the denominator is always the currency. Bitcoin is the only major asset whose supply cannot be expanded to paper over the problem. That is why Bitcoin holders care less about which type of inflation is running hot in any given quarter and more about the long-term trajectory of the currency itself.
The CPI is a useful tool for comparing consumer prices year over year. It is not the complete picture of inflation. Monetary and asset-price inflation can be running at two or three times the official CPI rate and never show up in the headline number. If you benchmark your wealth against CPI, you will feel like you are keeping up while your purchasing power against housing, equities, and scarce assets quietly erodes. Benchmark against hard-supply assets instead.
How inflation is measured: CPI vs PPI vs PCE
There is no single inflation number. Three measures matter and they often disagree.
Consumer Price Index (CPI)
Price changes for a fixed basket of goods and services that a typical urban household buys. Published monthly by the Bureau of Labor Statistics. Social Security cost-of-living adjustments, Treasury Inflation-Protected Securities (TIPS) adjustments, federal tax brackets, and IRMAA thresholds are indexed to versions of CPI verify×DON'T TRUST, VERIFYClaim: CPI methodology and basket weights are documented at the BLS, including the use of owners' equivalent rent for housing.Verify at: BLS CPI methodology FAQ ↗Housing uses owners' equivalent rent (an imputed rental value), which is the most-debated component because it does not track actual home-purchase prices.. The basket is fixed; it may not reflect current spending patterns. The housing component (owners' equivalent rent) is imputed from rental surveys, which is contested.
Producer Price Index (PPI)
Price changes received by domestic producers for their output, before goods reach consumers. PPI changes typically flow through to CPI with a lag of a few months, which makes it a leading indicator verify×DON'T TRUST, VERIFYClaim: The Producer Price Index measures wholesale-stage prices and is published monthly by the BLS.Verify at: BLS Producer Price Indexes ↗PPI covers final demand, intermediate demand, and crude materials; "PPI Final Demand" is the headline most often cited..
PCE deflator (Personal Consumption Expenditures)
The Federal Reserve's preferred inflation measure. Published by the Bureau of Economic Analysis. The key methodological difference from CPI: PCE allows for substitution. If beef gets expensive and people switch to chicken, PCE captures the shift. CPI uses a fixed basket and misses the substitution. PCE typically prints slightly lower inflation than CPI for this reason verify×DON'T TRUST, VERIFYClaim: The PCE deflator is the Fed's preferred inflation gauge and uses a chain-weighted formula that allows for substitution.Verify at: BEA PCE Price Index ↗The Fed's "Statement on Longer-Run Goals" specifies the 2% target in PCE terms, not CPI. Core PCE (excluding food and energy) is the most-watched single number..
Core vs headline
Headline includes everything. Core excludes food and energy, which are volatile because of weather, supply shocks, and geopolitics. The Fed focuses on core PCE as its primary trend-inflation gauge, on the theory that food and energy prices add noise without changing the underlying signal.
What this means for your money
- The number the Fed targets (PCE) is typically lower than the number you see in headlines (CPI). The Fed may declare victory on inflation while groceries and gasoline still feel high.
- Social Security uses CPI-W, a wage-earner variant of CPI. Your actual basket may grow faster or slower than CPI-W, so the COLA may not protect your specific spending pattern.
- TIPS coupons adjust to CPI-U. If your spending tracks CPI closely, TIPS preserve real purchasing power. If it does not, the protection is partial. Detail at Cash Management and Social Security.
Real vs nominal interest rates
Nominal rate is the rate printed on your statement. Real rate is the nominal rate minus inflation. The real rate tells you whether your purchasing power is growing.
Real rate ≈ Nominal rate − Inflation rate
A 5% savings account is genuinely good when inflation is 2% (3% real). The same 5% account is a real loss when inflation is 7% (negative 2% real). The bank still pays you 5%, but each dollar buys less than it did when you deposited it.
For decisions that span more than a year, always think in real terms. Mortgages, student loans, retirement projections, and bond yields all need the inflation deduction to be comparable across time.
What this means for your money
- "High-yield savings accounts" advertised at 4% to 5% can still lose real purchasing power when inflation runs hotter.
- Fixed-rate mortgages get cheaper in real terms when inflation rises faster than expected. Borrowers benefit from unexpected inflation; savers and lenders lose.
- Bond yields quoted in newspapers are nominal. The real yield on TIPS is what you keep after inflation.
The Phillips Curve
A.W. Phillips documented a historical pattern in UK data published in 1958: low unemployment correlated with high wage growth (a proxy for inflation), and high unemployment with low wage growth verify×DON'T TRUST, VERIFYClaim: A.W. Phillips's original paper was "The Relation Between Unemployment and the Rate of Change of Money Wage Rates in the United Kingdom, 1861-1957," Economica 25(100), 1958.Verify at: JSTOR ↗The original paper plotted wage growth against unemployment. Later economists translated wage growth to consumer-price inflation; Phillips himself did not..
The intuition was straightforward. When unemployment is low, workers have bargaining power; wages rise, and higher wages flow through to higher prices. When unemployment is high, workers compete for jobs and price pressure cools.
By the 1960s, this had become the basis for activist policy: governments could pick a point on the curve. Slightly higher inflation in exchange for lower unemployment, or higher unemployment in exchange for lower inflation. The trade-off was treated as stable.
The 1970s broke it
Stagflation: simultaneous high inflation and high unemployment. The textbook trade-off said this should not happen. Milton Friedman and Edmund Phelps had independently predicted it would, on the argument that workers and firms adapt their inflation expectations. If workers expect 5% inflation, they demand wage increases of 5% or more; firms agree, expecting to charge higher prices. Prices and wages both rise. Unemployment returns to its "natural rate" but with higher inflation baked in. To get the same temporary unemployment benefit next time, the central bank has to deliver even more inflation, creating a spiral verify×DON'T TRUST, VERIFYClaim: Friedman's 1968 American Economic Association presidential address argued that the Phillips trade-off would break down once inflation expectations adjusted.Verify at: Friedman, "The Role of Monetary Policy," American Economic Review 58(1), 1968 ↗Phelps's parallel argument appeared in 1967-1968 papers. Both were vindicated by the 1970s experience..
The modern synthesis distinguishes a short-run Phillips Curve (the trade-off is real temporarily) from a long-run vertical Phillips Curve (no lasting trade-off; the economy returns to the natural rate of unemployment regardless of the inflation level).
What this means for your money
The Fed uses the Phillips Curve framework to set interest-rate policy. When unemployment falls below what the Fed considers the natural rate, the Fed raises rates preemptively to head off wage-price pressure. When unemployment rises, the Fed cuts rates to stimulate hiring. This is why your mortgage rate, your car-loan rate, and your savings yield all move on the unemployment report.
The 2021-2023 episode is the most recent stress test of the framework. The Fed held rates near zero while unemployment fell rapidly, partly because it had revised down its estimate of the inflation-triggering level. Inflation reached 9.1% (CPI-U headline) in June 2022. Whether this confirms or refutes the Phillips framework is actively debated; the empirical answer turns on whether the inflation was driven by demand (a Phillips story) or by supply shocks (a different story).
The Phillips Curve, Short-run vs Long-run
Methodology: stylized Phillips Curve following the Friedman-Phelps natural-rate synthesis. Stagflation point illustrates the 1970s breakdown of the simple trade-off.
- Federal Reserve Bank of St. Louis. M2 Money Stock (WM2NS) · fred.stlouisfed.org/series/WM2NS. $15.4T (Feb 2020) to $21.7T (Apr 2022 peak).
- U.S. Bureau of Labor Statistics. CPI-U June 2022 release · bls.gov/cpi. Year-over-year CPI peaked at 9.1% in June 2022.
- Federal Reserve Bank of San Francisco. "Lessons from the 1970s" · frbsf.org. Quadrupling of crude oil prices during the 1973–1974 embargo.
- S&P Dow Jones Indices. S&P 500 historical performance · spglobal.com. March 2020 low to January 2022 high: about doubled.
- Federal Reserve Bank of St. Louis. S&P/Case-Shiller U.S. National Home Price Index (CSUSHPINSA) · fred.stlouisfed.org/series/CSUSHPINSA. ~40% increase March 2020 to June 2022.
- U.S. Bureau of Labor Statistics. CPI methodology documentation on owner's equivalent rent, hedonic adjustment, and substitution bias · bls.gov/cpi/questions-and-answers. Also see the Boskin Commission Report (1996) for the original analysis of substitution bias.
- Friedman, Milton, and Anna Schwartz. A Monetary History of the United States, 1867–1960. Princeton University Press, 1963. The canonical statement of the monetary theory of inflation.
- Historical U.S. CPI (Bureau of Labor Statistics). The cumulative consumer-price decline of about 24% between 1929 and 1933 is the canonical U.S. deflation figure. See BLS historical tables · bls.gov/cpi/tables. Also Federal Reserve History, "The Great Depression" · federalreservehistory.org.
- Bernanke, B., Reinhart, V., and Sack, B. "Monetary Policy Alternatives at the Zero Bound." Federal Reserve Board Finance and Economics Discussion Series, 2004 · federalreserve.gov. The academic articulation of why a positive inflation buffer is useful as a monetary-policy shock absorber.
- Federal Reserve Bank of St. Louis. "Assets: Total Assets" (WALCL) · fred.stlouisfed.org/series/WALCL. Pre-crisis ~$900B, 2022 peak ~$8.97T.
- Federal Reserve Board. "Statement on Longer-Run Goals and Monetary Policy Strategy." First adopted 2012, updated 2020 · federalreserve.gov. The official explanation of the 2% target and the Fed's dual mandate.
Last updated 2026-04-18 · Not financial advice. Do your own research.
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