Natural Rate of Unemployment
The natural rate of unemployment is the rate of unemployment that prevails when the labour market is in equilibrium, with no cyclical deficiency in aggregate demand. It is the sum of frictional and structural unemployment, and it is sometimes called the non-accelerating inflation rate of unemployment, or NAIRU, in contexts where it is defined as the rate at which inflation is stable. The natural rate is not zero, because some unemployment is inevitable in a dynamic economy.
Components
The natural rate comprises frictional and structural unemployment. Frictional unemployment arises from the time it takes workers to search for and match with suitable jobs, and from the normal turnover of the labour market. Structural unemployment arises from mismatches between the skills and locations of workers and the requirements of available jobs, caused by technological change, deindustrialisation, or regional decline. Both are present even when aggregate demand is adequate.
Cyclical unemployment, by contrast, arises from a shortfall in aggregate demand and is the component that stabilisation policy can address. The observed unemployment rate equals the natural rate plus cyclical unemployment plus any deviation caused by shocks. Distinguishing the components is important for policy, since the appropriate response differs.
Determinants
The natural rate is influenced by several factors. Demographic change affects the composition of the labour force, since young and older workers experience higher unemployment. Labour market institutions, including unemployment benefits, employment protection, minimum wages, and collective bargaining, affect the incentives to search and to hire. Technological change and globalisation shift the demand for skills and can raise structural unemployment if adjustment is slow. Housing and transport affect geographic mobility, and childcare and family policy affect participation.
Tax and benefit systems influence the natural rate by altering the rewards to work and to hiring. High effective tax rates on labour, generous and long-duration unemployment benefits, and rigid wage structures can raise the natural rate by lengthening unemployment spells and reducing job creation. Reforms to these institutions can lower the natural rate, though they may have distributional consequences.
The NAIRU and inflation
The NAIRU is defined as the unemployment rate at which inflation neither rises nor falls, given the current inflation expectations and supply conditions. When unemployment falls below the NAIRU, inflation tends to accelerate, because labour markets tighten and wages rise; when unemployment exceeds the NAIRU, inflation tends to decelerate. The NAIRU is therefore a key reference for monetary policy, guiding judgements about how far the economy can expand without generating inflationary pressure.
Estimating the NAIRU is difficult because it is not directly observable and can shift over time with changes in institutions, demographics, and productivity. Estimates are uncertain and are subject to revision, which complicates the use of the concept in real-time policy. The NAIRU can also be affected by the level of unemployment itself, through hysteresis, meaning that prolonged high unemployment can raise the NAIRU.
Policy implications
The natural rate concept informs both stabilisation and structural policy. If unemployment is above the natural rate, demand-side policies can reduce cyclical unemployment without generating inflation. If unemployment is at or below the natural rate, further stimulus risks accelerating inflation, and structural measures are needed to lower the natural rate itself. Identifying which situation prevails requires real-time estimates and judgement.
Structural policies to reduce the natural rate include education and training to improve matching, active labour market programmes, reforms to tax and benefit systems to strengthen work incentives, and measures to improve mobility and to remove barriers to job creation. The design of these policies, and their effectiveness, vary across countries and depend on the underlying causes of the natural rate.
Estimation and uncertainty
Estimating the natural rate is difficult because neither the natural rate nor potential output is directly observable. Economists use statistical filters to separate trend from cycle in unemployment and output data, structural models that relate unemployment to its determinants, and estimates of the wage-setting and price-setting relationships that determine equilibrium unemployment. Each approach has limitations, and estimates are often revised substantially as new data arrive.
The uncertainty surrounding the natural rate has practical consequences. Policymakers who overestimate the natural rate may keep policy too tight, leaving unemployment unnecessarily high. Those who underestimate it may stimulate too much, generating inflation. Because estimates are uncertain and change over time, policy must rely on a range of indicators and on judgement, and central banks often emphasise the robustness of their decisions to alternative estimates.
Structural reforms
Structural reforms aim to lower the natural rate by improving the functioning of the labour market. Measures include reducing the tax wedge on labour, reforming unemployment benefits to strengthen work incentives while maintaining adequate insurance, improving education and training systems, and removing barriers to job creation and mobility. The design of these reforms is important, since poorly designed measures can reduce welfare without improving employment.
The evidence on the effects of structural reform is mixed and context-dependent. Some reforms, such as reducing the tax wedge for low-wage workers, have been associated with higher employment, while others, such as weakening employment protection, have had smaller effects and have increased insecurity. Successful reform typically combines flexibility with support, helping workers to move between jobs while maintaining adequate protection and income.