Short-term and long-term growth

Economic growth means an economy’s real output increases over time. Real GDP is the relevant measure because it removes changes caused merely by inflation.

Short-term economic growth, or actual growth, occurs when an economy uses more of its existing productive capacity, increasing current real output. On a production possibilities curve, this is shown by movement from a point inside the PPC towards a point on the curve. Idle or underused resources are employed more fully, but the curve doesn’t shift.

Long-term economic growth, or potential growth, occurs when an expansion of productive capacity raises the economy’s maximum sustainable output. This may come from a larger or better-quality labour force, capital accumulation, improved education and health, or technological progress. Greater efficiency and stronger institutions can also contribute.

Actual growth makes fuller use of resources the economy already has. Potential growth increases how much the economy is capable of producing. Both can be shown using a PPC.

Growth in the AD/AS model

In the short run, higher aggregate demand shifts AD to the right. Equilibrium real output rises as long as the aggregate supply curve isn’t vertical. If substantial spare capacity exists, output can increase sharply while the price level rises relatively little. Closer to full employment, the same increase in AD causes more inflation and adds less to output.

A rightward shift in long-run aggregate supply from LRAS1 to LRAS2 shows long-term growth. Full-employment output increases. When aggregate demand also grows sufficiently, actual output can rise with productive capacity. Without enough demand growth, the economy may gain extra capacity but not use all of it immediately.

Measuring economic growth

The annual growth rate is calculated from real GDP:

A negative result shows that the economy contracted.

A recession is a phase of the business cycle when real economic activity declines significantly. It is commonly accompanied by falling real output and rising cyclical unemployment, and is often associated with a decrease in aggregate demand.

Consequences of growth

Growth can raise living standards, meaning people’s material access to goods and services. An increase in real GDP per capita is usually stronger evidence than an increase in real GDP alone. If output grows by 3% while population grows by 4%, average output per person has fallen. Real GDP per capita is still an average, however, so it doesn’t show distribution, unpaid activity, leisure or environmental damage.

Employment, profits and tax revenue may all improve as the economy grows. Governments can spend the additional revenue on healthcare, education and infrastructure. In Vietnam, for example, sustained growth helped finance wider electricity access and public services. The rise in output was therefore linked to concrete improvements in household welfare, rather than merely producing a larger GDP figure.

Environmental effects can go either way. Extra manufacturing, transport and resource extraction may increase pollution, carbon emissions and the depletion of natural capital. On the other hand, higher incomes and tax revenue can fund public transport, renewable energy and cleaner production. Environmental sustainability depends on what is produced and how it is produced, as well as how effectively environmental costs are regulated.

The impact on income distribution is uncertain too. If growth is concentrated in a few urban industries or among owners of capital, inequality may widen. It may narrow when growth creates accessible employment, raises low wages and finances redistribution. Ireland’s expansion of high-productivity industries, for instance, raised national income but also highlighted regional and housing inequalities. The distribution of those gains mattered as much as the growth rate itself.

Growth doesn’t automatically lead to better welfare. Its value depends on growth per person and its duration, along with how gains are distributed and whether environmental damage can be avoided or reversed.

Measurement

Unemployment is a labour-market condition where people of working age have no work, are available to work and are actively looking for employment. Countries differ in the working-age limits and survey rules they use.

The labour force includes the economically active population: employed people plus unemployed people who are actively seeking work. It excludes many full-time students and retired people, for example, as well as people who aren't looking for employment.

$$LF=E+U$$

Here, $LF$ is the labour force (people), $E$ is the number employed (people) and $U$ is the number unemployed (people).

The unemployment rate is calculated as:

$$u=\frac{U}{LF}\times 100$$

Here, $u$ is the unemployment rate (%). The denominator must be the labour force—not the total population or the entire working-age population.

Difficulties of measurement

Official figures are useful, but they don't provide a perfect count of unused labour.

• Discouraged workers want employment but have stopped searching because they believe no suitable work is available. Since they are normally excluded from the labour force, measured unemployment may be understated.
• Underemployment occurs when employed people work fewer hours than they want or use substantially fewer skills than they possess. They are recorded as employed, even though their labour resources aren't fully used.
• Informal or illegal workers may describe themselves as unemployed, which causes overstatement.
• Some benefit claimants may hide paid work. Survey sampling, changing definitions and seasonal adjustments can also affect the published figure.

Comparisons between countries therefore need consistent definitions. Changes in labour-force participation should also be considered alongside the unemployment rate.

Causes and types

Cyclical unemployment, also called demand-deficient unemployment, results from insufficient aggregate demand during a downturn. Lower spending cuts firms' sales and output. Since labour demand is derived from demand for output, firms need fewer workers. On an AD/AS diagram, this appears as a deflationary or recessionary gap, with equilibrium output below full-employment output.

If wages are sticky downwards, falling labour demand may leave the current wage above the new market-clearing wage. The quantity of labour supplied then exceeds the quantity demanded, causing unemployment.

Structural unemployment is long-lasting unemployment caused by a mismatch between workers and the jobs available. Technology may change the skills firms require, or an industry may relocate to another region. International competition can permanently reduce an industry's labour demand, while labour-market rigidities may prevent adjustment. Structural unemployment can exist alongside unfilled vacancies: jobs are available, but they may be in the wrong occupation or place.

A permanent drop in demand for a particular kind of labour shifts that market's labour-demand curve to the left. Employment falls and, over time, the equilibrium wage may fall too. Workers remain unemployed if they cannot retrain or relocate.

A binding minimum wage can create another rigidity. When the legal minimum is above the equilibrium wage, the quantity of labour supplied exceeds the quantity demanded. This surplus of labour represents unemployment in the affected market. Its size depends on how responsive labour demand and supply are, as well as compliance with the law.

Seasonal unemployment is recurring unemployment caused by predictable changes in labour demand at certain times of the year. Examples include people employed only during a ski season or a major annual harvest.

Frictional unemployment is temporary unemployment caused by the time people and employers need to find suitable matches. It includes new entrants looking for their first job and workers moving between jobs. Some frictional unemployment is unavoidable in a changing economy. It may improve matching when workers take time to find suitable positions.

The natural rate of unemployment is the unemployment rate that exists when the economy is at full-employment output. It consists of structural, seasonal and frictional unemployment; cyclical unemployment is excluded. So, “full employment” does not mean nobody is unemployed.

Costs of unemployment

Personal costs include lost income and lower living standards. Confidence may decline, while prolonged joblessness can erode skills. Health and family relationships may also deteriorate, particularly when access to insurance or housing depends on employment.

Social costs may include greater poverty, exclusion and homelessness, along with poor health and crime. These outcomes don't affect every individual automatically, but persistent unemployment can put considerable pressure on communities.

Economic costs include lost real output because labour is operating below its productive potential. Income-tax and consumption-tax revenue fall, while government spending on benefits and retraining rises, so the budget balance may worsen. Long periods of unemployment can also harm future productive capacity as workers lose skills or leave the labour force.

Inflation and the CPI

Inflation is a sustained rise in an economy's average price level over time. A price increase for just one product doesn’t count as inflation.

The consumer price index (CPI) is a weighted price index. It compares the cost of a representative basket of consumer goods and services with its cost in a base period. By convention, the base-period CPI equals 100 index points.

The inflation rate between two periods is:

$$\pi_t=\frac{CPI_t-CPI_{t-1}}{CPI_{t-1}}\times 100$$

where $\pi_t$ is the inflation rate in the current period (%), $CPI_t$ is the consumer price index in the current period (index points) and $CPI_{t-1}$ is the consumer price index in the preceding period (index points).

If quantities purchased are given, use them to calculate expenditure on each item in each year. Then find the total cost of the basket, construct the CPI and calculate inflation. The basket quantities must stay constant across the years being compared. Otherwise, the calculation mixes price changes with quantity changes.

Limitations of the CPI

Because the CPI is an average, it doesn’t necessarily reflect the cost of living faced by a particular household.

• Households don’t all buy the same basket. For example, rising childcare costs affect a young family differently from a retired household, although both face the same national CPI.
• Fixed weights can become outdated when consumers switch away from products that have become relatively expensive.
• The basket takes time to include new products and changes in consumption habits.
• Separating quality improvements from pure price increases is difficult. If a product becomes much better, ignoring that quality gain makes its higher price overstate inflation.
• Prices differ across regions, retailers and sales channels, so choosing one representative price can be difficult.
• The CPI generally leaves out some asset prices and may differ from the measure of inflation relevant to firms or exporters.

Causes of inflation

Demand-pull inflation is inflation caused when aggregate demand grows faster than the economy's productive capacity. An increase in consumption, investment, government spending or net exports shifts AD to the right. Both real output and the price level rise. Near full employment, capacity constraints cause proportionately more of the change to appear as inflation.

Cost-push inflation is inflation caused by an economy-wide rise in production costs, which shifts short-run aggregate supply to the left. Triggers may include higher energy or imported-input prices, indirect taxes, disrupted supply chains and wages growing faster than labour productivity. The price level rises as real output falls. This is especially awkward because inflation and unemployment may rise together.

Costs of high inflation

High or unpredictable inflation makes future costs, revenues and real returns uncertain. Firms may respond by delaying investment, which reduces capital formation and long-term economic growth.

Inflation also redistributes income and wealth. People whose nominal incomes adjust slowly lose purchasing power. Borrowers, meanwhile, may gain at the expense of lenders because they repay debt using money with a lower real value. The final effect depends on whether inflation was anticipated and whether wages, benefits and contracts are indexed.

Saving becomes less attractive when the nominal interest rate paid to savers is below inflation, since the real value of savings falls. Unexpected inflation can therefore change decisions about saving and borrowing.

If domestic inflation is higher than inflation among trading partners, exports become less price competitive and imports become relatively more attractive, other things equal. Net exports may fall, along with employment in trade-exposed industries.

Rapid changes in the general price level also weaken the price mechanism. Firms struggle to tell whether a price movement is a relative-price signal or simply part of economy-wide inflation, so resources may be allocated inefficiently. Uncertainty, reduced investment and distorted decisions can then lower economic growth.

Disinflation and deflation

Disinflation is a fall in a positive rate of inflation. The price level is still rising, just more slowly. For instance, a drop in inflation from 6% to 3% is disinflation rather than deflation.

Deflation is a sustained fall in the average price level, shown by a negative inflation rate. One possible cause is a persistent leftward shift of AD. Both output and the price level fall, while cyclical unemployment rises.

A rightward shift of SRAS can also cause deflation, perhaps because productivity improves or input prices fall. Here, the price level falls while real output rises. Supply-driven deflation is generally less damaging than demand-deficient deflation.

Costs of deflation

When households expect prices to fall, they may delay purchases of durable goods. Lower consumption pushes AD further left and encourages even more postponement. This deflationary spiral is associated with cyclical unemployment and business bankruptcies.

Firms experience uncertainty and declining nominal revenue, which may reduce investment and employment. Deflation also raises the real value of fixed nominal debt. Households, businesses and governments have to repay money with greater purchasing power. Debtors lose, while creditors and people holding cash gain, creating redistributive effects.

Falling prices and wages may interfere with price signals and the allocation of resources. Monetary policy can also lose effectiveness if nominal interest rates are already close to zero while pessimistic households and firms remain unwilling to borrow. The costs depend heavily on how long deflation lasts and what caused it. A brief, productivity-led fall in prices is very different from a prolonged collapse in demand.

Using expenditure weights

A weighted price index combines several price changes in one index number. Each item’s influence depends on its share of expenditure, so a frequently purchased product or one that accounts for substantial spending has more influence than a minor purchase.

Using fixed base-period quantities, a CPI can be constructed as:

The numerator gives the cost of the base-period basket at current prices. The denominator gives the cost of that same basket at base-period prices. Multiplying by 100 sets the base index at 100.

A reliable calculation follows these steps:

1. Multiply each base-period price by its base-period quantity, then sum the expenditures.
2. Multiply each current price by the same base-period quantities and sum again.
3. Divide the current basket cost by the base basket cost, then multiply by 100.
4. If two CPI figures are available, calculate inflation using the percentage-change formula from the preceding section.

Some datasets provide percentage expenditure weights instead of quantities. In this case, multiply each price relative by its weight, then sum the weighted relatives. Check that the percentage weights total 100%; if they don’t, the final index will be distorted.

A comparison requiring context

Both unemployment and high inflation reduce economic welfare. There is no universally correct way to rank their costs; the judgement depends on their rates and causes, as well as their duration, predictability and distribution.

For people who cannot find work, unemployment brings an immediate and concentrated loss. It reduces output and incomes, worsens the government budget and can cause lasting harm through lost skills, ill health and poverty. Prolonged structural unemployment is especially costly because a recovery in aggregate demand may not be enough to reconnect workers with available jobs.

Moderate inflation that is stable and anticipated is usually less damaging than an equally dramatic episode of unemployment. When inflation is predictable, contracts and interest rates can adjust. High or accelerating inflation is different. It erodes purchasing power, discourages saving and investment, damages competitiveness and may weaken confidence in money itself.

The type of inflation makes a difference too. Demand-pull inflation near full employment may occur alongside strong output and employment. Cost-push inflation, however, combines rising prices with falling output. Trying to reduce cost-push inflation by suppressing demand could create more unemployment without fixing the original supply problem.

Real-world experience shows this contrast. Spain's unemployment following the global financial crisis was particularly costly because many younger workers remained jobless for extended periods, risking permanent losses in skills and earnings. Argentina's repeated high-inflation episodes, by contrast, disrupted contracts and saving across most households. The effects were especially severe for people unable to protect their income or wealth. The cases aren't interchangeable: Spain's centres on unused labour and persistence, while Argentina's concerns unstable money and redistribution.

Any balanced judgement must ask who bears each cost and how long it lasts. During a deep recession, reducing unemployment may reasonably take priority, even if inflation rises slightly. Where inflation is rapid, unanchored and embedded in expectations, restoring price stability may be more urgent despite the short-run costs to output and employment.

Debt, deficits and measurement

Government debt is the total stock of outstanding financial liabilities that the public sector owes to domestic and foreign creditors. As a stock, it is measured at a specific point in time.

A budget deficit occurs when government expenditure exceeds government revenue over a stated period, so it is a flow. Deficits normally add to debt because governments must borrow to cover the shortfall. A budget surplus can reduce debt, though valuation changes and other financial transactions may also alter the recorded stock.

Debt is commonly compared with national income:

The debt-to-GDP ratio tells us more than the debt figure on its own. GDP gives an indication of the economy's tax base and its broad capacity to service debt. The ratio may rise when debt increases, nominal GDP falls, or both happen at once.

A sustainable debt level is a debt position that a government can continue to service without default, persistently accelerating borrowing or making economically damaging changes to taxation and spending. No single ratio is safe for every country. Sustainability depends on interest rates and economic growth, as well as the currency and maturity of the debt. Investor confidence, revenue-raising capacity and what the borrowing finances also matter.

Costs of high debt

Debt servicing is government expenditure on interest and required principal repayments. A large servicing burden carries an opportunity cost. Revenue paid to creditors cannot be used at the same time to fund healthcare, education, infrastructure or poverty reduction.

Credit-rating agencies may view lending to a highly indebted government as riskier. A lower credit rating can increase the interest rate that lenders demand. This raises debt-service costs and may create a vicious circle in which higher borrowing costs produce further deficits.

Future taxpayers may have to pay higher taxes, while future governments may need to cut public spending. Either response can weaken aggregate demand and restrict policy choices, especially during a recession.

Debt, however, is not automatically harmful. Borrowing may prevent a severe downturn or finance productive infrastructure. If this raises future GDP and tax revenue, the debt becomes easier to service. The central question is not simply “How large is the debt?” but “Can it be serviced, and what was acquired with the borrowing?”

Why the objectives may conflict

Low unemployment can exist alongside low inflation when productive capacity expands. In the short run, though, the two objectives may conflict when policy changes aggregate demand.

During a recessionary gap, an increase in AD raises output and the derived demand for labour, so cyclical unemployment falls. The price level rises as well, although the initial inflationary effect may be modest if there is extensive spare capacity.

Close to full-employment output, firms face shortages of labour, components and machinery. Any further increase in AD brings a relatively small gain in output but stronger demand-pull inflation. Policies that try to push unemployment below the natural rate are therefore likely to intensify inflationary pressure.

Which objective takes priority depends on the circumstances. A country recovering from a prolonged recession may tolerate somewhat higher inflation to reduce joblessness and poverty. By contrast, an economy that relies on price-sensitive exports may give more weight to price stability, since inflation relative to competitors harms export demand and employment.

This conflict isn't inevitable. A rightward shift of SRAS or LRAS can reduce inflationary pressure while increasing output and employment. An adverse supply shock, however, can worsen both objectives at the same time by raising cost-push inflation and unemployment.

The short-run Phillips curve

The short-run Phillips curve (SRPC) shows an inverse short-run relationship between the inflation rate and the unemployment rate, other things equal. Moving up the curve means lower unemployment alongside higher inflation. Moving down means higher unemployment and lower inflation.

These movements reflect changes in aggregate demand. Expansionary demand conditions increase output and demand for labour, but they also raise the price level. Contractionary demand conditions ease inflationary pressure while creating cyclical unemployment.

An economy moves along a single SRPC only while supply conditions and inflation expectations stay unchanged. Higher production costs or expected inflation can shift the SRPC to the right, resulting in more inflation at every unemployment rate. Improved productivity or lower expected inflation can shift it to the left.

The long-run Phillips curve

The long-run Phillips curve (LRPC) is vertical at the natural rate of unemployment. In the monetarist/new classical model, it shows that no permanent long-run trade-off exists between inflation and unemployment.

Suppose the economy starts at the natural rate. An increase in AD raises inflation and temporarily lowers unemployment, causing movement along the initial SRPC. Workers and firms then adjust their inflation expectations, so nominal wages and other input costs rise. SRAS shifts left, unemployment returns to its natural rate and the SRPC shifts right. Inflation remains higher, but unemployment isn’t permanently lower.

In the associated AD/AS model, the economy starts at full-employment output. An increase in AD creates a temporary inflationary gap. As input prices rise, SRAS shifts left until output returns to its potential level at a higher price level.

This conclusion rests on particular assumptions. The Keynesian view allows the economy to remain below full employment when wages and prices adjust slowly. Demand management may therefore reduce unemployment for a substantial period. By contrast, the monetarist/new classical view emphasises the adjustment of expectations and argues that repeated demand expansion can’t keep unemployment below its natural rate indefinitely.

Real-world evidence needs careful interpretation. When inflation and unemployment move in opposite directions, the economy may be moving along an SRPC. When both rise—as happened in many economies after major energy-price shocks—a rightward shift of the SRPC caused by adverse supply conditions is the more convincing explanation, rather than a failure to interpret a downward-sloping curve correctly.

High growth and low inflation

In the short term, growth caused by higher AD may conflict with low inflation. If substantial spare capacity exists, output can rise with little inflationary pressure. Once the economy approaches full employment, additional demand pushes up the price level much more sharply. Long-term growth can reduce this conflict by shifting LRAS to the right, allowing demand and output to expand without putting the same pressure on prices.

Growth and environmental sustainability

Environmental sustainability means maintaining economic activity without depleting natural resources or damaging ecological systems in ways that compromise future generations. Growth driven by fossil fuels, congestion, deforestation or intensive extraction may raise current GDP but reduce future welfare.

This conflict isn’t unavoidable. Cleaner energy and efficient public transport can help, as can technologies that use fewer resources per unit of output. Costa Rica, for example, has combined economic development with extensive renewable electricity and forest restoration. Green technology still uses resources, though, so it doesn’t make unlimited material growth costless. The scale and composition of output continue to matter.

Growth and equity

Equity in income distribution is a condition in which the distribution of income is regarded as fair, taking account of both outcomes and opportunities. Growth may conflict with equity when most of the gains go to highly skilled workers, owners of capital or regions that are already prosperous.

Growth can also create employment and expand the tax base available to governments. They can use this revenue to fund education, healthcare, social protection and regional infrastructure. Inclusive growth is economic growth whose opportunities and benefits are broadly shared across society. Whether growth improves equity depends on labour-market access, ownership, wage changes, taxation and public spending—not just the headline growth rate.

These conflicts need evaluation rather than slogans. The same growth rate may be inflationary or non-inflationary, environmentally destructive or relatively clean, and unequal or inclusive. What happens depends on the source of growth, the amount of existing spare capacity, government institutions and how costs and benefits are distributed over time.