The Keynesian revolution and its heirs

Detail

1. The crisis that broke Say's law

• Say's law (classical idea): "supply creates its own demand". Whatever is produced will be bought. So long-lasting unemployment cannot exist.
• The Great Depression (Class 12, Introduction) proved this wrong:
• US unemployment rose from 3% to 25% (1929–33).
• US output fell by about 33% (1929–33).

• Factories stood idle because people were not buying goods.

• Why this broke the classical view:

• Classical economists said wages and prices would fall, so all workers would find jobs again.
• Instead, unemployment stayed high for years.
• So the problem was too little demand, not too little supply.

2. John Maynard Keynes: the person (NCERT box)

• Born 1883. Studied at King's College, Cambridge.
• The Economic Consequences of the Peace (1919): he argued that the harsh peace terms after World War I would not last. He predicted the post-war peace would break down.
• The General Theory of Employment, Interest and Money (1936): NCERT says macroeconomics "was born" with this book.

• Macroeconomics is the study of the economy as a whole: total output, total employment, the general price level. It also studies how sectors (households, firms, government, the rest of the world) depend on each other.

• NCERT also calls him "a shrewd foreign currency speculator". He made money trading currencies himself.

• The General Theory came out in February 1936. It introduced the consumption function, effective demand and liquidity preference, and gave new importance to the multiplier and the marginal efficiency of capital [2][6].

3. Core Keynesian ideas

(The full model is in income-determination-keynes.)

a) Effective demand

• Effective demand is the total spending the economy actually carries out (spending backed by money). It decides how much is produced and how many people get jobs.
• Output and employment depend on demand. Supply does not create its own demand.
• Identity: Y = O = D. National income (Y) = value of national output (O) = national expenditure (D) [6].
• IMF summary: aggregate demand (spending by households + businesses + government) is "the most important driving force in an economy" [3].
• Aggregate demand in an open economy: AD = C + I + G + (X − M), that is consumption + investment + government spending + net exports.

b) Involuntary unemployment

• Involuntary unemployment means people are willing to work at the current wage but cannot find jobs.
• It is different from voluntary unemployment, where people choose not to work at the current wage.
• Keynes said it exists because demand is too low. Cutting wages may not help, because lower wages mean lower spending.
• Keynesians also say prices and wages are sticky: they "respond slowly to changes in supply and demand" [3]. So the economy does not fix itself quickly.

c) Liquidity preference

• Liquidity means how easily an asset can be used to buy things. Cash is the most liquid asset.
• Liquidity preference is the demand for money as a way to store wealth. Keynes said this demand, together with the money supply, sets the rate of interest.
• People hold money for three motives: transactions (daily buying), precaution (emergencies) and speculation (waiting for bond prices to change).
• Liquidity trap: at a very low interest rate, extra money supply does not raise investment. People simply hold the extra money as speculative balances. Keynes used this to explain the long Depression of the 1930s [2].
• Policy meaning: in a deep slump, monetary policy stops working, so fiscal policy (government spending) must do the job.

d) The multiplier

• The multiplier (k) shows that ₹1 of new spending raises total income by more than ₹1. One person's spending becomes another person's income, who then spends part of it again.
• The IMF describes it this way: "output changes by some multiple of the increase or decrease in spending that caused the change" [3].
• Formula: k = ΔY / ΔI = 1 / (1 − MPC) = 1 / MPS
• MPC (marginal propensity to consume): the share of each extra rupee of income that people spend.

• MPS (marginal propensity to save) = 1 − MPC.

• Worked example:

• MPC = 0.8, so MPS = 0.2, and k = 1 / 0.2 = 5.
• The government spends an extra ₹100 crore on roads.
• Total income rises by 100 × 5 = ₹500 crore.

• Round by round: ₹100 → ₹80 → ₹64 → ₹51.2 … and the total adds up to ₹500 crore.

• Key point: the higher the MPC, the bigger the multiplier. Poorer households spend more of each extra rupee, so money given to them has a bigger multiplier effect.

e) Animal spirits

• Animal spirits are emotions such as confidence, optimism and fear. They drive business investment.
• Investment depends on expected future profit. Keynes called this the marginal efficiency of capital [2].
• Why investment is unstable:
• Business mood changes → expected profits change.
• Investment rises or falls sharply.
• Through the multiplier, income and jobs swing even more.

f) Fallacy of composition and the paradox of thrift

• Fallacy of composition: wrongly assuming that what is true for one part is also true for the whole.
• Paradox of thrift:
• One household saving more is wise. It becomes richer.
• If all households save more at the same time, total spending falls.
• Firms sell less → they cut output and jobs → incomes fall.

• With lower incomes, total saving may not rise at all, and may even fall.

• Worked example:

• Income = ₹1,000 crore. Everyone decides to save ₹50 crore more.
• Demand falls by ₹50 crore. With k = 5, income falls by ₹250 crore, to ₹750 crore.

• Saving is taken out of a smaller income, so total saving ends up about where it was.

• Lesson: microeconomic logic (one person) cannot simply be applied to macroeconomics (the whole economy).

g) Policy: deficit spending and Bretton Woods

• In a slump, the government should spend more than it earns. This is deficit spending, also called counter-cyclical fiscal policy: spend more in bad times and less in good times.
• Fiscal deficit = total expenditure − (revenue receipts + non-debt capital receipts). In simple terms, it is how much the government must borrow in a year.
• Bretton Woods Conference (1944): Keynes helped design the post-war system. It created the IMF (to keep exchange rates stable and help with balance-of-payments problems) and the World Bank (IBRD, to lend for reconstruction and development).

4. The welfare state

• Welfare state: a state that takes main responsibility for its citizens' well-being through social security, health, education and redistribution (moving income from rich to poor).
• Link to Keynes: welfare spending also acts as an automatic stabiliser. In a slump, benefit payments rise on their own, so demand does not fall as much.
• Beveridge Report (1942), UK: it named five "giants" to defeat:
• Want (poverty), Disease, Ignorance (lack of education), Squalor (bad housing), Idleness (unemployment).

• It led to Britain's post-war social insurance system and the National Health Service (NHS), 1948.

• Indian roots: Directive Principles of State Policy (DPSPs), Part IV:

Article	Provision
Art. 38	State to promote the welfare of the people; a social order based on justice (welfare state)
Art. 39	Adequate livelihood; no concentration of wealth and means of production
Art. 41	Right to work, to education, and to public assistance in unemployment, old age, sickness
Art. 43	Living wage and decent working conditions
Art. 47	Raise the level of nutrition and improve public health

• Rights-based welfare: these laws turned DPSP goals into rights that people can claim in law:
• MGNREGA (2005): a legal guarantee of 100 days of wage work a year to rural households. It works like a Keynesian employer of last resort.

• NFSA (2013): a legal right to subsidised food grains.

• The "freebies" debate:

• Merit welfare: spending that builds long-term ability, such as nutrition, schooling and health.
• Freebies: giveaways (often before elections) that do little for long-term ability and strain budgets.
• The real question is where one ends and the other begins, and whether the state can afford it.

5. The heirs of Keynes

a) Neoclassical synthesis

• It joins Keynes and classical economics: Keynes for the short run (prices are sticky, demand matters) and classical economics for the long run (prices adjust, supply matters).
• J.R. Hicks's IS-LM model (1937): a diagram of Keynes's ideas.
• IS curve: combinations of interest rate and income where the goods market is in balance (investment = saving).
• LM curve: combinations where the money market is in balance (liquidity preference = money supply).

• Where they cross, both markets are in balance.

• Paul Samuelson made the synthesis popular in textbooks.

• Phillips curve: a trade-off between inflation and unemployment. Lower unemployment comes with higher inflation. (Cross-ref: inflation topic.)
• Its fall:
• Keynesian economics dominated after World War II until the 1970s [3].
• Then many rich economies had stagflation: high inflation together with slow growth [3].
• The simple Phillips curve could not explain this. Monetarism (Milton Friedman) gained ground.
• Keynesians then adopted the monetarist critiques. They linked the short run and the long run better and accepted that money is neutral in the long run (more money only raises prices, not real output) [3].

b) New Keynesian economics (1980s)

• It gives Keynesian conclusions a micro foundation: it explains why markets do not clear, using how firms and workers actually behave.
• Sticky prices and wages (John Taylor, Guillermo Calvo): wages and prices are fixed by contract for some time. So they cannot adjust at once.
• Menu costs (N. Gregory Mankiw, 1985): the cost of changing prices (printing new price lists, updating systems). Even small costs make firms slow to change prices.
• Efficiency wages (George Akerlof and Janet Yellen): firms pay above the market wage so workers put in more effort and stay longer. Wages then do not fall to the level that clears the labour market, so unemployment remains.
• Imperfect competition: firms have some power to set prices, so prices do not adjust perfectly.
• Policy link: New Keynesian models are the base of today's inflation-targeting central banks, including the RBI. RBI works under flexible inflation targeting, where the Monetary Policy Committee targets CPI inflation of 4% ± 2%.
• Revival: the global financial crisis of 2007–08 brought a "resurgence in Keynesian thought" [3].

c) Post-Keynesian: Hyman Minsky's financial instability hypothesis

• Core idea: "stability breeds instability".
• Long good times → borrowers and lenders become careless.

• Debt keeps rising → the financial system becomes fragile → crisis.

• Three stages of finance:

Stage	What income can pay	Example (loan ₹100, interest ₹10/yr)
Hedge finance	Both interest and principal	Income ₹40/yr: pays ₹10 interest + ₹30 principal
Speculative finance	Interest only; the principal must be rolled over (re-borrowed)	Income ₹10/yr: pays interest, borrows again to repay principal
Ponzi finance	Neither; debt is repaid only if asset prices keep rising	Income ₹5/yr: must sell the asset at a higher price to repay

• Minsky moment: the sudden collapse of asset prices after a long, debt-fuelled boom. Paul McCulley coined the term in 1998. The 2008 global financial crisis is the classic case.
• Indian relevance: it is a warning about fast credit growth in the boom years before the twin balance sheet problem, and about asset bubbles more generally.

d) Modern Monetary Theory (MMT)

• Main thinkers: Warren Mosler, L. Randall Wray, Stephanie Kelton.
• Claim: a government that issues its own currency can always print money to pay its debts in that currency. So it cannot be forced to default.
• Its real limit is inflation, not solvency (the ability to pay debts). Spending should stop only when the economy's real resources are fully used and prices start rising.

• Why MMT fits India poorly: 1. FRBM Act (2003) (Fiscal Responsibility and Budget Management Act): a law that sets targets for the fiscal deficit and debt.

  • Current status: the fiscal deficit is 4.4% of GDP (RE 2025-26), which meets the 2021-22 promise to bring it below 4.5% by 2025-26 [4].
  • Target: 4.3% of GDP (BE 2026-27) [5].
  • The new anchor is a debt glide path: central government debt of 50 ± 1% of GDP by 2030-31 (March 2031), down from about 56.1% of GDP in 2025-26 [5][4]. 2. The rupee is not a reserve currency. Other countries do not hold it in large amounts. Too much money creation could weaken it sharply → imports cost more → inflation. 3. History of high inflation in India, which hurts the poor most. 4. High deficits could lead to rating downgrades and capital outflows. Foreign investors leave → the rupee falls → borrowing costs rise.

• Worked example (why the deficit matters):

• GDP = ₹350 lakh crore; fiscal deficit at 4.4% = ₹15.4 lakh crore of new borrowing in one year.
• Under MMT, this could be "financed" by printing money. In India, that would risk inflation and a weaker rupee.

Prelims Hooks

• The General Theory of Employment, Interest and Money was published in 1936. NCERT says macroeconomics was born with it.
• Multiplier k = 1/(1 − MPC) = 1/MPS. If MPC = 0.75, k = 4. A higher MPC gives a bigger multiplier.
• Paradox of thrift is an example of the fallacy of composition: if everyone saves more, total saving may not rise.
• Liquidity trap: at very low interest rates, extra money is simply held, so monetary policy fails [2].
• IS-LM model is by J.R. Hicks (1937). IS = goods market in balance; LM = money market in balance.
• Menu costs = Mankiw (1985). Efficiency wages = Akerlof–Yellen. Both are New Keynesian, not Post-Keynesian. This is a common trap.
• Minsky's three stages in order: hedge → speculative → Ponzi. The term "Minsky moment" was coined by Paul McCulley (1998), not by Minsky.
• Beveridge Report (1942): five giants are Want, Disease, Ignorance, Squalor, Idleness. It led to the NHS (1948).
• DPSP pairs: Art. 43 → living wage; Art. 47 → nutrition and public health; Art. 41 → right to work and public assistance.
• Stagflation (1970s: high inflation + slow growth) ended the dominance of Keynesian economics [3]. The 2007–08 crisis revived it [3].

Mains Points

• Counter-cyclical fiscal policy in India: Keynesian stimulus (for example, extra spending during COVID-19 and high public capital expenditure since) must be weighed against the FRBM debt glide path. Fiscal deficit fell to 4.4% (RE 2025-26) and is targeted at 4.3% (BE 2026-27), with debt aimed at 50 ± 1% of GDP by 2030-31 [4][5]. The argument: spend on high-multiplier capital expenditure rather than on freebies.
• Welfare state vs freebies (GS-II/III): MGNREGA and NFSA put DPSPs (Arts. 38, 41, 43, 47) into practice. They also act as automatic stabilisers. But unfunded giveaways by states strain budgets. A test to use: does the spending build human capital and have a high multiplier, or is it only consumption with no lasting gain?
• Minsky and financial stability: long credit booms (India's infrastructure lending boom before the twin balance sheet problem; unsecured retail loans and NBFCs now) show that "stability breeds instability". This supports macroprudential regulation by the RBI, such as higher risk weights and countercyclical capital buffers.
• Why MMT does not suit emerging economies: India lacks a reserve currency, has a history of high inflation, and depends on foreign capital. So its real limit is external and inflation risk, not only domestic resources. That makes fiscal rules such as FRBM necessary, not optional.