Phillips Curve In The Long Run

The Phillips Curve, a cornerstone of macroeconomic theory, illustrates the inverse relationship between inflation and unemployment. While the short-run Phillips Curve is widely accepted, the long-run version presents a more nuanced and complex picture.

Understanding the Phillips Curve: A Brief Overview

The Phillips Curve, named after economist A.W. Phillips, initially described an empirical relationship observed in the United Kingdom: periods of high unemployment tended to coincide with low inflation, and vice versa. This observation led to the belief that policymakers could exploit this trade-off, choosing a desired level of unemployment and accepting the corresponding level of inflation.

However, this simplistic view began to unravel in the 1970s, a period marked by stagflation – the simultaneous occurrence of high inflation and high unemployment. This phenomenon challenged the traditional Phillips Curve and led to the development of the concept of the Long-Run Phillips Curve.

The Short-Run Phillips Curve (SRPC)

The SRPC depicts the inverse relationship between inflation and unemployment in the short term. This relationship is based on the idea that as aggregate demand increases, firms hire more workers, leading to lower unemployment and higher wages. These higher wages, in turn, push up production costs, which are then passed on to consumers in the form of higher prices (inflation).

Key assumptions of the SRPC:

• Sticky Wages: Wages are assumed to be slow to adjust to changes in economic conditions due to factors like labor contracts and worker resistance to pay cuts.
• Inflation Expectations: Inflation expectations are assumed to be relatively stable in the short run.

The Long-Run Phillips Curve (LRPC)

The LRPC, in contrast to the SRPC, suggests that there is no trade-off between inflation and unemployment in the long run. Instead, the LRPC is depicted as a vertical line at the natural rate of unemployment (also known as the non-accelerating inflation rate of unemployment or NAIRU).

Key Concepts for Understanding the LRPC:

• Natural Rate of Unemployment (NAIRU): This is the level of unemployment that prevails in an economy when it is operating at its potential output. It includes frictional and structural unemployment, but not cyclical unemployment.
• Adaptive Expectations: This theory suggests that people form their expectations about future inflation based on past inflation rates.
• Rational Expectations: This theory posits that individuals make optimal forecasts of the future using all available information.

The Development of the Long-Run Phillips Curve

The concept of the LRPC emerged from the work of economists like Milton Friedman and Edmund Phelps, who argued that the short-run trade-off between inflation and unemployment was only temporary. They emphasized the role of expectations in shaping the long-run relationship.

The Friedman-Phelps Argument:

1. Initial Situation: Assume the economy is at the natural rate of unemployment with stable inflation.
2. Government Intervention: The government tries to lower unemployment by increasing aggregate demand.
3. Short-Run Effect: Initially, unemployment falls, and inflation rises, as predicted by the SRPC.
4. Expectations Adjustment: Workers notice the rising inflation and demand higher wages to maintain their real purchasing power.
5. Shift in SRPC: The SRPC shifts upward as firms face higher labor costs and pass them on to consumers through higher prices.
6. Long-Run Outcome: Unemployment returns to the natural rate, but at a higher level of inflation. This suggests that attempts to keep unemployment below the natural rate will only lead to accelerating inflation.

In essence, Friedman and Phelps argued that any attempt to exploit the short-run Phillips Curve trade-off would ultimately be self-defeating, leading to higher inflation without any lasting reduction in unemployment.

Why is the Long-Run Phillips Curve Vertical?

The vertical LRPC implies that in the long run, monetary policy can only affect the price level (inflation) and not real variables like unemployment. This is because:

• Wages and Prices Adjust: In the long run, wages and prices become fully flexible and adjust to reflect changes in monetary policy.
• Rational Expectations Prevail: Individuals and firms eventually incorporate the effects of monetary policy into their expectations, neutralizing its impact on real variables.
• Real vs. Nominal Variables: The LRPC highlights the classical dichotomy – the separation of real and nominal variables in the long run. Monetary policy, a nominal variable, cannot permanently affect real variables like unemployment.

Implications for Policymakers

The LRPC has significant implications for policymakers:

• Focus on Structural Reforms: To lower the natural rate of unemployment, policymakers should focus on structural reforms that improve the functioning of the labor market, such as:
  • Reducing barriers to entry for new businesses
  • Improving education and training programs
  • Reforming unemployment benefits
• Control Inflation: Monetary policy should primarily focus on maintaining price stability. Attempts to use monetary policy to lower unemployment below the natural rate will only lead to higher inflation.
• Credibility is Key: The effectiveness of monetary policy depends on its credibility. If the central bank is perceived as being committed to price stability, inflation expectations will be anchored, making it easier to control inflation.

Factors that Can Shift the Long-Run Phillips Curve

While the LRPC is vertical, its position can shift over time due to factors that affect the natural rate of unemployment. Some of these factors include:

• Changes in Demographics: Shifts in the age, gender, or skill composition of the labor force can affect the natural rate of unemployment.
• Technological Change: Technological advancements can lead to structural unemployment as some jobs become obsolete.
• Changes in Labor Market Institutions: Changes in laws and regulations, such as minimum wage laws or unemployment benefits, can affect the natural rate of unemployment.
• Globalization: Increased international trade and competition can lead to structural changes in the economy, affecting the natural rate of unemployment.

The New Keynesian Perspective on the Phillips Curve

While the traditional LRPC is vertical, some economists, particularly those of the New Keynesian school, argue that there may be a small trade-off between inflation and unemployment even in the long run. They emphasize the role of nominal rigidities and real rigidities in preventing wages and prices from fully adjusting.

Nominal Rigidities: These refer to the stickiness of wages and prices due to factors like:

• Menu Costs: The cost of changing prices.
• Staggered Wage Contracts: Wage contracts that are negotiated at different times, preventing wages from adjusting simultaneously.

Real Rigidities: These refer to factors that prevent firms from adjusting their production levels in response to changes in demand, such as:

• Coordination Failures: Firms may be reluctant to lower wages or prices if they fear that other firms will not follow suit.
• Customer Relationships: Firms may be hesitant to raise prices for fear of losing customers.

The New Keynesian Phillips Curve (NKPC):

The NKPC incorporates these rigidities and suggests that the LRPC may be slightly downward sloping, implying that there is still a small trade-off between inflation and unemployment in the long run. However, this trade-off is likely to be much smaller than the short-run trade-off.

Criticisms of the Phillips Curve

The Phillips Curve, both in its short-run and long-run versions, has faced criticism from various perspectives:

• The Lucas Critique: Robert Lucas argued that the Phillips Curve relationship is not stable because it is based on expectations that are likely to change when policies change. He argued that policymakers need to take into account the effects of their policies on expectations.
• Supply Shocks: The Phillips Curve framework does not adequately account for supply shocks, such as oil price increases, which can lead to both higher inflation and higher unemployment.
• Measurement Issues: The natural rate of unemployment is difficult to measure accurately and can change over time, making it difficult to use the Phillips Curve for policy purposes.
• Globalisation: In an increasingly globalized world, domestic inflation is influenced by global factors, weakening the relationship between domestic unemployment and inflation.

The Phillips Curve in the 21st Century

The relationship between inflation and unemployment has appeared to weaken in recent decades, leading some economists to question the relevance of the Phillips Curve. Several factors may have contributed to this weakening:

• Globalization: Increased global competition has put downward pressure on wages and prices, reducing the sensitivity of inflation to domestic unemployment.
• Anchored Inflation Expectations: Central banks have become more successful in anchoring inflation expectations, making inflation less responsive to changes in unemployment.
• Demographic Changes: Aging populations in many developed countries have led to a decline in labor force participation rates, potentially affecting the natural rate of unemployment.
• Technological Change: Automation and the rise of the gig economy have changed the nature of work, potentially affecting the relationship between unemployment and wages.

Despite these challenges, the Phillips Curve remains a valuable tool for understanding the relationship between inflation and unemployment. However, it is important to recognize its limitations and to consider other factors that may be influencing inflation.

Conclusion

The Long-Run Phillips Curve provides a crucial understanding of the relationship between inflation and unemployment in the long term. It highlights that while a short-run trade-off may exist, attempts to exploit it will ultimately lead to higher inflation without any lasting reduction in unemployment. Policymakers should focus on structural reforms to improve the functioning of the labor market and maintain price stability through credible monetary policy. While the Phillips Curve has faced criticism and its relevance has been questioned in recent decades, it remains a valuable framework for understanding the complex dynamics of inflation and unemployment. The evolving global economic landscape requires a nuanced understanding of the Phillips Curve and its limitations to effectively guide economic policy.