1. Inflation and Unemployment
No 11. Chapter 12
Inflation and Unemployment

2. Introduction
Thus far we have only tangentially discussed inflation and unemployment, despite the political attention received by these two variables
This chapter examines the implications of our theory for these two variables, as well as their importance for society

3. Steady Inflation Revisited
First recall our money neutrality proposition: In the long run, an increase in M leads to a proportionate rise in P, with real variables in our model left unchanged.
We would expect that steady growth of M would result in steady growth of P, other things held equal. If P rises steadily, this is inflation.
I often like to distinguish a one-time increase in P from steady increases in P
For conceptual purposes, I think of inflation as a sustained increase in P, not a one-time increase

4. More on Steady Inflation
Recall the equation for the LM Curve in our model:
In the classical model (or the Keynesian long-run) both output and the interest rate are will not be affected by changes in the money supply (money neutrality again), and if inflation is steady, expected inflation will also be constant
In a steady inflation, M and P are going up in proportion, and all variables on the right-hand side of the LM equation are constant.

5. A Change in the Steady Inflation Rate
If money grows at 3% per year in our model, the inflation rate will be 3% per year; if money grows at 7% per year, the inflation rate will be 7% per year.
Note: This does assume that output is not changing.
However, if we have been having steady money growth of 3% and then change to steady money growth of 7%, once we reach a new steady state with 7% inflation, the real money supply must be smaller (since expected inflation is larger on the RHS below):

6. A One-Time Jump in P
When the expected inflation rate rises (as it eventually must when the steady inflation rate changes), the LM curve shifts to the right, putting upward pressure on price.
This effect is above and beyond the direct proportional effect of M on P.
Illustrate with a diagram! As the economy moves to the new steady inflation path, measured inflation must temporarily exceed the new higher steady rate.
This extra price rise is what produces the lower real money supply in the higher inflation steady state.

7. A Change in Steady Inflation
Log P t*
Time

8. Steady Inflation: IS-LM and AD-AS
With steady money growth and steady inflation, IS and LM are not moving
LM is subject to offsetting effects of money and price movements.
AD steadily shifts up and to the right, so that P rises. So long as the inflation is expected, we are heading straight up the vertical LRAS curve.

9. AD-AS with Steady InflationP
LRAS P3 P2
AD3 P1
AD2
AD1 Y

10. Can We Have Inflation in a Keynesian Model?
We have interpreted the Keynesian model as a fixed price model. In the short-run price is “stuck” so there is no price movement.
However, Keynesian economists know that prices eventually change
The model can be modified to even permit ongoing inflation
Prices might be set at the beginning of a period, and then remain stuck until the next period starts
However, prices could steadily rise from period to period, even though they are inflexible for long times within periods.

11. The Keynesian Model with Steady InflationP
LRAS P3
SRAS3 P2
SRAS2
AD3 P1
SRAS1
AD2
AD1 Y

12. The Classical Model with Monetary Misperceptions
Recall the “misperceptions” extension of the classical model. In this model, SRAS curves are upward sloping, not horizontal.
Some variants of Keynesian models might also have SRAS curves that slope upward, so the following analysis does not really require that we adopt all of the classical model assumptions

13. Lucas Misperceptions Model with Steady Inflation
LRAS
SRAS3 [Pe=P3]
SRAS2 [Pe=P2] P3
SRAS1 [Pe=P1] P2
AD3 P1
AD2
AD1 Y

14. The Classical Model with Monetary Misperceptions
In the misperceptions model:
If aggregate demand rises faster than expected, inflation is higher than was expected, and we move up the SRAS curve
If aggregate demand rises more slowly than expected, then inflation is lower than expected, and we move down the SRAS.

15. Expected Money Growth

16. Unexpected Money Growth

17. Output and Unemployment in the Misperceptions Model
When price rises faster than expected, some workers misinterpret this as a relative price increase rather than a general price increase
If a baker thinks the relative price of bread has risen, he will work harder; he also finds it worthwhile to hire more workers (perhaps offering a higher nominal wage)
Job seekers begin to find acceptable wage offers more quickly and take jobs faster and the number unemployed falls.
Workers initially see these job offers as attractive, because they have not yet perceived the higher price level (they incorrectly perceive the “real wage offer)

18. Inflation and Unemployment
The preceding story suggests that as long as inflation is expected, unemployment will be at its normal rate (consistent with normal searching and turnover in the job market).
But when the general price level rises faster than expected, the higher inflation is accompanied by lower unemployment.
Unemployment and inflation are inversely related as aggregate demand fluctuates (holding expected inflation fixed).

19. An Expectational Phillips Curve: Equation Form

20. Phillips Curve Facts

21. A Menu of Possible Choices?
Can we exploit this curve? Can we obtain lower unemployment if we are just willing to tolerate higher inflation?
Our earlier discussion of inflation and output suggests not—output gains associated with inflation, and the employment fluctuations associated with output, only occurred when expectations were incorrect
Expectations eventually change, so one can not permanently lower unemployment by going from low steady inflation to high steady inflation

22. Long and Short-Run Phillips Curves

23. Short-run Phillips Curves

24. Long-run Phillips Curve

25. More Data

26. Can the Natural Rate of Unemployment Change?
Yes. Classical economists might note that technical change is often accompanied by job mismatches, hence changes in the natural or equilibrium level of unemployment
Keynesians would rely on the efficiency wage argument
A negative productivity shock can reduce labor demand--at a fixed efficiency wage, the pool of unemployed would grow and would stay higher persistently
Also, changes in labor supply behavior could change the natural rate of unemployment.

27. Nobel Prizes
Both Milton Friedman and Edmund Phelps won Nobel Prizes for work on the “expectational” Phillips curve model (and other things)
The model explains why an apparent statistical relation between unemployment and inflation cannot be exploited by policymakers.
If a policymaker tries to lower unemployment by way of a higher inflation rate, the attempt might be initially successful, but ultimately inflation stays higher while unemployment returns to its natural rate.
Keeping unemployment low would require that inflation always be higher than expected, implying accelerating inflation (hence the term NAIRU: the non-accelerating inflation rate of unemployment)

28. Another Nobel
Frequently policymakers assume that historical behavioral regularities observed in the past will prevail in the future (i.e. the Phillips Curve).
However, changing policy rules will often change behavior. We cannot assume that empirical relationships observed under one set of policy behavior will persist under a different policy regime.
This simple point, known as the Lucas Critique, was, in part, responsible for the Nobel awarded to Robert Lucas.
One of its implications is that we should be wary of embedding ad hoc empirical regularities into a theory. Theory should be derived from basic assumptions about rational behavior.

29. Policy: What are the Costs of Unemployment?
Unemployment is apparently costly
People who are not working could have produced output, which has value, but that is lost.
On the other hand, when I don’t work, I have more leisure, so it is not correct to infer that the loss to society is equal to the value of the forgone output.
Classical economists believe that much search is voluntary, hence optimal
Keynesians see a much larger cost of unemployment.
In the efficiency wage model, there is true involuntary unemployment

30. Policy: What are the Costs of Inflation?
In a world with money neutrality there are no real effects of inflation
Even in the Keynesian model, money neutrality prevails in the long run.
Sometimes individuals seem to believe that inflation robs them of real purchasing power.
In fact, a steady inflation raises wages and prices in proportion and inflation does not reduce society’s overall real standard of living. So this is not a cost of inflation.

31. More on the Costs of Inflation
A steady inflation does produce what are sometimes caused “shoe-leather” costs
Unanticipated inflation is redistributive, and inflation volatility increases risk for borrowers and lenders
In the presence of high inflation, relative prices are more difficult to observe, leading to a less effective functioning of prices in their role of allocating goods and services
Inflation-Tax interactions

32. A Final Question
So why do we sometimes see economic policy produce high inflation rates?

33. The End