Saturday, March 27, 2010

The Gap Effect, and the Expectation Effect


People talk about inflation a LOT, so its probably a good idea know what it is. If you've survived macroeconomics without knowing what inflation is up until this point, congratulations, you live a seriously charmed life.

For the rest of us, lets reiterate:

Inflation is any rise in the general price level (P)

Inflation can be temporary/transitory (the price level increases to a new equilibrium price level, where it stays put for a while) or it can be sustained/persistant (the price level rises continuously over time)

In classical economics, aggregate demand shocks and aggregate supply shocks cause TEMPORARY inflation (one-time jumps in the price level) as a side effect of gap inflation. In this chapter, we are more concerned with exploring the causes of sustained inflation (which, as we will learn, is affected by people's expectations). We're also going to look at what causes accelerating inflation.

On a very basic level, prices can rise for two different reasons
1) There is a decrease in supply (this is called cost-push inflation)
2) There is an increase in demand (this is called demand-pull inflation)

Inflation - A rise in the consumer price index
Inflation Rate - The percentage change in the consumer price index
Zero Inflation - A situation where there is no percentage change in the consumer price index
Stable Inflation - A situation where the inflation rate remains relatively constant over time (ie: inflation is 2% for seven years in a row)
Accelerating Inflation - The inflation rate increases over time (ie: inflation is 2% in 1991, 4% in 1992, 8% in 1993, and 13% in 1994)
Disinflation - The inflation rate decrease over time (ie: inflation is 16% in 1991, 9% in 1992, 5% in 1993, and 3% in 1994)
Deflation - A negative rate of inflation: the consumer price index goes down (so goods end up costing less)

Low inflation: 1-3%
Medium inflation: 3-6%
High inflation: Over 6%
Hyperinflation: Over 20%

Why are we concerned with inflation? Because too much inflation inflicts a bunch of costs on society. Here are some of them:
-It decreases the purchasing power of people who are on fixed incomes (both contractually and in terms of pensionary incomes)
-It can arbitrarily redistribute income
-It undermines the efficiency of the price system by distorting relative prices (so its harder for consumers to tell if they are getting a good deal or if they are getting ripped off if the general price level is continuously in flux)


One last important concept is NAIRU, which is the non-accelerating inflationary rate of unemployment. Basically, this is the rate of unemployment present in an economy when there are no inflationary or recessionary gaps (when Y is at Y*). This does not mean that there is no unemployment- only that there is no GAP unemployment (there can still be frictional and structural unemployment). NAIRU is also sometimes called "full employment," or U*.

We're going to look at why NAIRU is called NAIRU in this chapter



Okay... why do people's wages change?

There are two factors which can explain why people's wages change
1) The gap effect
2) The expectation effect

-Basically, this is demand-pull inflation caused by excess demand in the labour market.
-In an inflationary gap, we get GAP INFLATION. Y is larger than Y*, U is smaller than U*, and there is an excess demand for labour. As a result, firms are forced to raise wages in order to keep employees. The result of this rise in wages is that average costs rise (which, in turn, causes the short run aggregate supply to shift to the left, correcting the inflationary gap).
-In a recessionary gap, we get GAP DEFLATION. Y is smaller than Y*, U is greater than U*, and there is an excess supply of labour. As a result, firms can safely lower employee wages without the risk of losing employees (its better to have a low-paying job than no job at all). This, in turn, causes average costs to fall, which shifts short run aggregate supply to the right, correcting the inflationary gap.
-When there is no gap, there is NO INFLATION. Y equals Y*, U equal U*, demand and supply of labour are equal, wages remain constant, average costs remain constant, and the short run aggregate supply remains constant (as do prices).

The Phillips Curve shows the inverse relation between the unemployment rate and the rate of changes in nominal wages.

Basically, as unemployment gets higher, wage increases get smaller and smaller, and eventually, turn into wage decreases (salary cuts).

Classical economists ONLY considered the gap effect to be a source of inflation, and believed that gaps would only create a temporary period of inflation. They also believed that if there was no gap, that there would be no increase in wages...

They were entirely correct... there is also...

-Here, expected inflation is taken into account when employees are negotiating wage demands with their employers
-Here, inflation is like a "self fulfilling prophecy". If employees believe that there will be inflation of a certain level over the next year, they will negotiate for higher wages to account for that inflation. This, in turn, increases firms' average costs, which shifts the SRAD curve to the left, effecting CAUSING an increase in prices in-step with what employees predicted. In other words, preemptively adjusting wages for expected inflation can MANUFACTURE real inflation!

Causes of expectation inflation:
-Expectation inflation can be caused by backward-looking, where people assume that past rates in inflation will continue into the future (people believe that history repeats itself)
-At the same time, if an economy has an extremely volatile inflation rate, it may take time for people to develop a psychological trend to respond to inflation- it takes a while to figure out how the pattern works and predict accurately for the future.
-Expectation inflation can also be forward-looking. Workers could look at governments' macroeconomic policies to predict what future changes may be in store (they can prognosticate).
-The main thing to remember is that in economics, we assume that people are RATIONAL BEINGS with their own best interests at heart. People try to use all available information to the best of their ability, and for the most part, they are correct. People can adjust rapidly to changes.

The TOTAL EFFECT: Changes in money wages are a combination of the gap effect and the expectation effect
-In this way, we can decompose an increase in the rate of wage changes into the gap effect (excess demand for labour) and the expectation effect (psychology)
-We can think of the expectation effect as the "cake" and the gap effect as the "icing", which causes increased wages changes on top of expected changes
-The total effect can be either positive or negative.

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