Modern Monetary Theory (MMT) is a heterodox macroeconomic framework arguing that a government which issues its own free-floating, non-convertible currency (such as the United States, United Kingdom, Japan, or Australia) faces no purely financial constraint on spending in that currency. The real constraints, MMT proponents argue, are inflation and the availability of real resources — labour, materials, energy — not tax revenue or bond markets.
Key claims associated with MMT include:
- Taxes do not fund spending at the federal level in a sovereign-currency system; rather, taxes create demand for the currency and remove purchasing power to manage inflation.
- Bond issuance is a monetary-policy operation, draining reserves and setting interest rates, rather than a financing necessity.
- Full employment can be pursued through a federally funded Job Guarantee, which also acts as an automatic price anchor and countercyclical stabiliser.
- Inflation, not solvency, is the binding limit on fiscal policy.
The framework draws on the chartalist tradition of Georg Friedrich Knapp (The State Theory of Money, 1905), the functional finance of Abba Lerner, and the balance-sheet accounting of Hyman Minsky and Wynne Godley. Its most prominent contemporary advocates include economists Stephanie Kelton, L. Randall Wray, Bill Mitchell, Pavlina Tcherneva, and Warren Mosler. Kelton's The Deficit Myth (2020) brought the theory to a wider audience.
MMT is contested. Critics — including Larry Summers, Kenneth Rogoff, Paul Krugman, and former IMF chief economist Olivier Blanchard — argue it understates inflation risks, political constraints on raising taxes to cool an overheating economy, and the dangers for countries without reserve-currency status or with significant foreign-currency debt. The 2021–2023 global inflation surge intensified this debate, with opponents citing it as evidence against MMT-style fiscal expansion and proponents attributing inflation primarily to supply shocks and corporate pricing power rather than excess demand.
MMT does not apply straightforwardly to currency-pegged economies, dollarised states, or eurozone members, which lack monetary sovereignty.
Example
In 2020, US economist Stephanie Kelton's book *The Deficit Myth* drew on MMT to argue that pandemic-era federal spending was not limited by the national debt but by inflation risk.
Frequently asked questions
No. MMT argues that deficits are not financially constrained for a currency issuer, but they do matter because excessive spending relative to productive capacity causes inflation.
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