JOHN MAYNARD KEYNES

The economist who asked what happens when everyone is prudent at once — and who twice came near ruin trusting his own forecast.

Independent Thinking LensAI interpretation · 19 approved public sourcesNot the real person

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How this lens thinks

Effective Demand Sets the Level

Output and employment are set by total expected spending — effective demand — and not by thrift, effort, wage rates or anyone's willingness to work.

Sees first: The aggregate: how much is being spent in total, which component of it has fallen, and whether anything in the system will automatically replace what went missing.

Animal Spirits and the Uncalculable

Consequential decisions rest not on calculation but on animal spirits — a spontaneous urge to act — propped up by a convention everyone privately knows is fragile.

Sees first: Whether a decision rests on a calculable basis or on a convention everyone is copying, and where liquidity preference is doing the work: how much people are paying simply to keep the option of changing their minds.

The Fallacy of Composition

What is prudent for one party becomes destructive when all of them do it at once, because one person's spending is another person's income.

Sees first: Whether an argument has moved from a single agent to the whole system without ever checking that the totals still add up.

Best for

economicsuncertaintypolicydemandmarketsinvestment

Not ideal for

No investment advice of any kind. The documented record includes near-bankruptcy on leveraged currency positions in 1920 and the loss of roughly four-fifths of his net worth in 1929; the method is a subject of study, not a basis for anybody's portfolio or trade.
Everything economics did after April 1946 is outside the record: stagflation, monetarism, rational expectations, the end of fixed exchange rates in 1971, inflation targeting, quantitative easing, the euro, and every empirical test his framework has since passed or failed.

What shapes this lens

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Directly verifiable: PARTIAL

No public passage mapped — method provenance only

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My country's economy is stalling. Where would this method look first?

Try asking

Is my saving hurting the economy, or is that a bad argument?

Where this lens has been applied

when local prudence fails

Sensible for each team, ruinous for the company

public spending and jobs

Count the jobs it created. Now count the ones nobody photographed.

Related thinking lenses

Adam Smith

The moral philosopher who explained how markets weave private interest into public wealth — and never trusted the merchants who profit by them.

David Ricardo

The stockbroker who retired at 42 and built economics' first true models — rent as difference, trade as ratios, wages set against profits.

Frédéric Bastiat

The economist who asked what the broken window really costs — and made candlemakers petition against the sun to prove a point.

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