The Keynesian Perspective
The Business Cycle and the Keynesian Question
Economies do not grow smoothly at a steady rate year after year; instead, output tends to cycle around its long-run trend, sometimes growing faster than average, sometimes slower, and occasionally shrinking outright during a recession. The Keynesian perspective, developed in response to observing deep and prolonged downturns, asks two central questions: what causes these cycles, and can government policy moderate them? Unlike views that treat the economy as naturally self-correcting toward full employment fairly quickly, the Keynesian perspective argues that an economy can remain stuck well below its potential output for an extended period unless something actively pushes it back toward full employment, which is the foundation for the policy conclusions this perspective is best known for.
Aggregate Demand and Its Components
Aggregate demand is the total demand for a country’s goods and services, made up of consumption spending by households, investment spending by businesses, government spending, and net exports, the difference between what a country exports and imports. Keynesian analysis places particular emphasis on the idea that aggregate demand is not automatically stable and can shift unexpectedly. Consumption spending depends heavily on household confidence about the future; if households in a manufacturing town suddenly grow uncertain about job security, precautionary saving tends to rise and consumption spending falls, even before any actual job losses occur. Investment spending is especially sensitive to business expectations about future demand and profitability, since a firm deciding whether to build a new production line is essentially betting on how strong sales will be years into the future, which makes investment spending one of the most volatile components of aggregate demand from one period to the next.
Sticky Wages and Prices: Why Recessions Can Persist
A central building block of Keynesian economics is that wages and prices are sticky, meaning they adjust only slowly to changes in demand rather than falling quickly enough to restore full employment on their own. One explanation for sticky wages is the coordination problem: even if workers might hypothetically accept a wage cut during a downturn as long as everyone else’s wages fell too, there is no simple mechanism in a decentralized economy for coordinating such a widespread reduction, so individual employers who cut wages unilaterally risk hurting morale and losing their best workers to competitors. Prices can be sticky for a related reason known as menu costs, the real costs a business incurs when changing prices, including the time spent updating price lists, contracts, and advertising, as well as the risk of confusing or frustrating customers with frequent price changes. Because both wages and prices adjust slowly, when aggregate demand falls, much of the initial adjustment shows up as reduced output and higher unemployment rather than lower prices, and an economy can remain in this depressed state for a considerable period without some outside push.
The Expenditure Multiplier
The expenditure multiplier is the idea that an initial change in spending produces a larger, more-than-proportionate change in total GDP, because one person’s spending becomes another person’s income, which that person then partly spends as well. Suppose a regional government spends ten million dollars building a new bridge; the construction workers and material suppliers who receive that money then spend a portion of their new income at local shops and restaurants, whose owners in turn spend part of their increased income elsewhere, and so on. If each round of recipients spends, say, sixty percent of the additional income they receive, the eventual total increase in economic activity from the original ten-million-dollar project can end up considerably larger than ten million dollars. This multiplier effect is central to Keynesian policy recommendations, since it implies that a given amount of government spending, or a tax cut that boosts household spending, can have an economic impact larger than its initial dollar value.
The Phillips Curve: Unemployment and Inflation
Early Keynesian-influenced research identified an apparent tradeoff between unemployment and inflation, later named the Phillips curve, in which periods of lower unemployment tended to coincide with higher inflation, and periods of higher unemployment tended to coincide with lower inflation. For a time, some policymakers treated this relationship as a stable menu of choices, believing they could select a preferred combination of unemployment and inflation through fiscal and monetary policy. However, this apparent tradeoff broke down in later decades, when several economies experienced periods of simultaneously high unemployment and high inflation, a combination economists call stagflation, which the simple Phillips curve relationship could not explain. This experience taught economists that the unemployment-inflation relationship is not fixed but can shift over time, depending on factors such as how workers and firms come to expect future inflation, which complicates using the Phillips curve as a simple policy tool.
Keynesian Policy Prescriptions
Because Keynesian analysis holds that aggregate demand can remain too low to support full employment for an extended period, its central policy prescription is that government can use fiscal policy, spending changes or tax changes, to shift aggregate demand back toward the level consistent with full employment. If an economy is in a recession, with output below potential, Keynesian policy calls for expansionary measures, such as increased government spending or tax cuts that boost household and business spending, to shift aggregate demand to the right. If an economy is instead overheating, with output above sustainable potential and inflationary pressure building, Keynesian policy calls for the opposite: contractionary measures, such as spending cuts or tax increases, to shift aggregate demand back to the left. Keynes himself was careful to separate this argument about the appropriate overall level of aggregate demand from any claim that government should set prices, manage individual industries, or otherwise interfere with how individual markets allocate resources, arguing instead that markets generally do a good job matching buyers and sellers as long as overall demand is sufficient to support full employment.
Quick Revision Summary
The Keynesian perspective explains why economies can experience prolonged downturns rather than snapping back quickly to full employment on their own. Aggregate demand, made up of consumption, investment, government spending, and net exports, is not automatically stable, and can shift unexpectedly as household and business expectations change. Sticky wages and prices, driven by coordination problems and menu costs, mean that when aggregate demand falls, much of the adjustment shows up as reduced output and higher unemployment rather than falling prices. The expenditure multiplier means that a given change in spending can produce a larger, more-than-proportionate change in total GDP, since one person’s spending becomes another person’s income. The Phillips curve once suggested a stable tradeoff between unemployment and inflation, but this relationship broke down during periods of stagflation, showing it is not a fixed policy menu. Keynesian policy prescribes using government spending and taxation to shift aggregate demand toward full employment, without necessarily interfering in how individual markets operate.