Key points
Keynesian economics is based on two main ideas. First, aggregate demand is more likely than aggregate supply to be the primary cause of a short-run economic event like a recession. Second, wages and prices can be sticky, and so, in an economic downturn, unemployment can result.
The coordination argument states that downward wage and price flexibility requires perfect information about the level of lower compensation acceptable to other laborers and market participants.
The expenditure multiplier is a Keynesian concept that asserts that a change in autonomous spending causes a more than proportionate change in real GDP.
A macroeconomic externality occurs when what happens at the macro level is different from and inferior to what happens at the micro level.
Menu costs are costs firms face when changing prices.
Sticky wages and prices are wages and prices that do not fall in response to a decrease in demand or do not rise in response to an increase in demand.
The building blocks of Keynesian analysis
Keynesian economics focuses on explaining why recessions and depressions occur and offering a policy prescription for minimizing their effects. The Keynesian view of recession is based on two key building blocks:
Aggregate demand, AD, is not always automatically high enough to provide firms with an incentive to hire enough workers to reach full employment.
The macroeconomy may adjust only slowly to shifts in aggregate demand because of sticky wages and prices—wages and prices that do not respond to decreases or increases in demand.
Let's look at each of these two claims more closely. The first building block of the Keynesian diagnosis is that recessions occur when the level of household and business sector demand for goods and services is less than what is produced when labor is fully employed. In other words, the intersection of aggregate supply and aggregate demand occurs at a level of output less than the level of GDP consistent with full employment.
Suppose the stock market crashes, as occurred in 1929. Household wealth declines, and consumption expenditure follows. Businesses see that consumer spending is falling, which reduces expectations of the profitability of investment, so they decrease investment expenditure.
This seems to be what happened during the Great Depression since the physical capacity of the economy to supply goods did not alter much. No flood or earthquake or other natural disaster ruined factories in 1929 or 1930. No outbreak of disease decimated the ranks of workers. No key input price, like the price of oil, soared on world markets. The US economy in 1933 had just about the same factories, workers, and state of technology as it had had four years earlier in 1929—and yet the economy shrank dramatically.
Keynes recognized that the events of the Great Depression contradicted Say’s law, which states that supply creates its own demand. Although production capacity existed, the markets were not able to sell their products. As a result, real GDP was less than potential GDP.
Wage and price stickiness
Keynes also noticed that when AD fluctuated, prices and wages did not immediately respond as economists expected. Instead, prices and wages were “sticky,” making it difficult to restore the economy to full employment and potential GDP.
Keynes emphasized one particular reason why wages are sticky: the coordination argument. This argument points out that, even if most people would be willing—at least hypothetically—to see a decline in their own wages in bad economic times as long as everyone else also experienced such a decline, a market-oriented economy has no obvious way to implement a plan of coordinated wage reductions. There are a number of reasons why wages might be sticky downward, most of which center on the argument that businesses avoid wage cuts because they may in one way or another depress morale and hurt the productivity of the existing workers.
Some modern economists have argued in a Keynesian spirit that, along with wages, other prices may be sticky, too. Many firms do not change their prices every day or even every month. When a firm considers changing prices, it must consider two sets of costs. First, changing prices uses company resources—managers must analyze the competition and market demand and decide what the new prices will be, sales materials must be updated, billing records will change, and product labels and price labels must be redone. Second, frequent price changes may leave customers confused or angry—especially if they find out that a product now costs more than expected.
These costs of changing prices are called menu costs—because they are similar to the costs of printing up a new set of menus with different prices in a restaurant. Prices do respond to forces of supply and demand, but from a macroeconomic perspective, the process of changing all prices throughout the economy takes time.
To understand the effect of sticky wages and prices in the economy, consider Diagram A below, illustrating the overall labor market, and Diagram B, illustrating a market for a specific good or service.
The original equilibrium
As a result, a situation of excess supply—where the quantity supplied exceeds the quantity demanded at the existing wage or price—exists in markets for both labor and goods, and
The recovery after the Great Recession in the United States has been slow, with wages stagnant, if not declining. In fact, many low-wage workers at McDonalds, Dominos, and Walmart have threatened to strike for higher wages. Their plight is part of a larger trend in job growth and pay in the post-recession recovery.
The National Employment Law Project compiled data from the Bureau of Labor Statistics and found that, during the Great Recession, 60% of job losses were in medium-wage occupations. Most of them were replaced during the recovery period with lower-wage jobs in the service, retail, and food industries. You can see this data in the graphs above.
Wages in the service, retail, and food industries are at or near minimum wage and tend to be both downwardly and upwardly sticky. Wages are downwardly sticky due to minimum wage laws; they may be upwardly sticky if insufficient competition in low-skilled labor markets enables employers to avoid raising wages that would reduce their profits. At the same time, however, the Consumer Price Index increased 11% between 2007 and 2012, pushing real wages down.
The two Keynesian assumptions in the AD/AS Model
The two Keynesian assumptions—the importance of aggregate demand in causing recession and the stickiness of wages and prices—can be illustrated using an aggregate demand/aggregate supply, or AD/AS, diagram like the one below. Note that because of the stickiness of wages and prices, the aggregate supply curve is flatter than the supply curves in diagrams A and B above. In fact, if wages and prices were so sticky that they did not fall at all, the aggregate supply curve would be completely flat below potential GDP.
This outcome is an important example of a macroeconomic externality, meaning that what happens at the macro level is different from and inferior to what happens at the micro level. For example, a firm should respond to a decrease in demand for its product by cutting its price to increase sales. But if all firms experience a decrease in demand for their products, sticky prices in the aggregate prevent aggregate demand from rebounding—which would be shown as a movement along the AD curve in response to a lower price level.
The original equilibrium of this economy occurs where the aggregate demand
The expenditure multiplier
Another key concept in Keynesian economics is the expenditure multiplier. The expenditure multiplier is the idea that not only does spending affect the equilibrium level of GDP but that spending is powerful. More precisely, it means that a change in spending causes a more than proportionate change in GDP.
The reason for the expenditure multiplier is that one person’s spending becomes another person’s income, which leads to additional spending and additional income, and so forth, so the cumulative impact on GDP is larger than the initial increase in spending. The multiplier is important for understanding the effectiveness of fiscal policy, but it occurs whenever any autonomous increase in spending occurs. Additionally, the multiplier operates in a negative as well as a positive direction.
Thus, when investment spending collapsed during the Great Depression, it caused a much larger decrease in real GDP. The size of the multiplier is critical and was a key element in recent discussions of the effectiveness of the Obama administration’s fiscal stimulus package, officially titled the American Recovery and Reinvestment Act of 2009.
Summary
Keynesian economics is based on two main ideas. First, aggregate demand is more likely than aggregate supply to be the primary cause of a short-run economic event like a recession. Second, wages and prices can be sticky, and so, in an economic downturn, unemployment can result.
The coordination argument states that downward wage and price flexibility requires perfect information about the level of lower compensation acceptable to other laborers and market participants.
The expenditure multiplier is a Keynesian concept that asserts that a change in autonomous spending causes a more than proportionate change in real GDP.
A macroeconomic externality occurs when what happens at the macro level is different from and inferior to what happens at the micro level.
Menu costs are costs firms face when changing prices.
Sticky wages and prices are wages and prices that do not fall in response to a decrease in demand or do not rise in response to an increase in demand.
Self-check questions
Use the AD/AS model to explain how an inflationary gap occurs, beginning from the initial equilibrium in the diagram below.
An inflationary gap is the result of an increase in aggregate demand when the economy is at potential output. Since the aggregate supply curve is vertical at potential GDP, any increase in aggregate demand will lead to a higher price level—in other words, inflation—but no higher real GDP. You'll be able to see this if you draw
Suppose the US Congress cuts federal government spending in order to balance the federal budget. Use the AD/AS model to analyze the likely impact on output and employment. Hint: Take a look at the figure above.
A decrease in government spending will shift AD to the left.
Review questions
From a Keynesian point of view, which is more likely to cause a recession: aggregate demand or aggregate supply? Why?
Why do sticky wages and prices increase the impact of an economic downturn on unemployment and recession?
Explain what economists mean by menu costs.
Critical-thinking questions
Does it make sense that wages would be sticky downwards but not upwards? Why or why not?
Suppose the economy is operating at potential GDP when it experiences an increase in export demand. How might the economy increase production of exports to meet this demand, given that the economy is already at full employment?
Attribution
This article is a modified derivative of "The Building Blocks of Keynesian Analysis" by OpenStaxCollege, CC BY 4.0.
The modified article is licensed under a CC BY-NC-SA 4.0 license.
References
Harford, Tim. “What Price Supply and Demand?” http://timharford.com/2014/01/what-price-supply-and-demand/?utm_source=dlvr.it&utm_medium=twitter.
“Job Creation and Economic Recovery.” National Employment Law Project. http://www.nelp.org/index.php/content/content_issues/category/job_creation_and_economic_recovery/.