Money Illusion
Money illusion refers to the tendency of people to think in terms of nominal rather than real quantities, so that they are influenced by changes in prices and wages that have no effect on real purchasing power. The concept, central to Keynesian and behavioural analyses, challenges the assumption that economic decisions depend only on real variables.
Definition and Examples
Money illusion occurs when individuals base decisions on nominal amounts rather than on the purchasing power those amounts represent. A worker who accepts a wage cut in nominal terms only when prices are falling, but resists an equivalent real wage cut when prices are stable, exhibits money illusion. A saver who is satisfied with a nominal interest rate that is below the rate of inflation likewise ignores the real return.
The concept applies to consumption, saving, wage setting, and price setting. Where money illusion is present, changes in the nominal values of prices and wages have real effects, because agents do not fully adjust for inflation.
Evidence
Evidence for money illusion comes from surveys, experiments, and field data. Survey respondents often report that a nominal wage increase makes them better off even when prices have risen by the same amount, and that a nominal wage cut makes them worse off even when prices have fallen. Experiments find that participants respond to nominal rather than real changes in payoffs.
Field evidence includes the behaviour of wages and prices during periods of inflation and deflation, and the patterns of consumer spending and saving in response to nominal changes. The evidence suggests that money illusion is present but varies in magnitude across contexts and individuals.
Implications for Macroeconomics
Money illusion provides a source of nominal rigidity that can give monetary policy real effects. If workers resist nominal wage cuts, or if firms are reluctant to cut nominal prices, downward adjustment is impeded, and real wages may rise during deflation, worsening unemployment. This reasoning underlies the analysis of deflation and the case for policies to avoid it.
The concept also informs the analysis of the Phillips curve, particularly the trade-off between inflation and unemployment when expectations adjust slowly. If agents do not fully anticipate inflation, nominal wage growth can exceed or fall short of inflation, affecting real wages and employment.
Relationship to Rational Expectations
Rational expectations models generally assume that agents do not suffer from money illusion, so that nominal changes are neutral unless there are frictions. Behavioural models, by contrast, incorporate money illusion as a departure from full rationality, supported by evidence from psychology and economics.
The debate about the extent of money illusion is part of the broader debate about the microfoundations of macroeconomics. The evidence suggests that money illusion matters for some decisions and magnitudes, and that models incorporating it can explain patterns that purely real models cannot.
Psychological Foundations
The study of money illusion draws on psychology, particularly the finding that people evaluate outcomes relative to reference points and that nominal values often serve as salient references. The framing of a transaction in nominal terms can influence perception and decision-making, even when the real consequences are unchanged.
The concept also connects to the analysis of fairness. Surveys find that nominal wage cuts are often perceived as unfair, even when prices have fallen, while nominal wage freezes are more acceptable. These perceptions influence wage setting and can contribute to downward nominal rigidity.
Money Illusion and Wage Adjustment
The presence of money illusion affects the adjustment of wages to economic conditions. If workers resist nominal wage cuts, firms facing weak demand may reduce employment rather than wages, contributing to higher unemployment. This rigidity is asymmetric, since nominal wage increases are generally accepted, which can create inflationary pressure when demand is strong.
The asymmetry of nominal rigidity is central to the analysis of inflation and unemployment and to the case for policies that maintain low and stable inflation. It also informs the design of labour market institutions, since institutions that facilitate adjustment can reduce the costs of shocks.
Implications for Household Behaviour
Money illusion affects household decisions about consumption, saving, and debt. Households may increase consumption when nominal income rises, even if prices have risen proportionally, or fail to adjust saving for inflation, reducing real wealth over time. Borrowers and lenders may misjudge the real cost of debt and the real return on assets.
These effects have implications for financial stability and for the design of financial products. Disclosures that emphasise real values, and products that index payments to inflation, can help households make decisions that reflect real rather than nominal magnitudes.
Measuring Money Illusion
Measuring money illusion requires distinguishing responses to nominal changes from responses to real changes. Surveys and experiments that vary nominal and real magnitudes independently provide direct evidence. Field data, including the behaviour of wages and prices, and the patterns of consumption and saving, provide indirect evidence.
Estimates vary, and the magnitude of money illusion depends on context and on the salience of inflation. The evidence suggests that money illusion is present in some decisions and magnitudes, and that incorporating it improves the ability of models to match observed behaviour. The concept therefore remains an important element of behavioural and macroeconomics.