by Jim Rose in global financial crisis (GFC), great depression, inflation targeting, macroeconomics, monetary economics Tags: CPI bias, deflation, inflation, monetary policy

All agree that the consumer price index (CPI) is biased and overstates inflation. In 1996, economists hired by the Senate Finance Committee estimated that the U.S. CPI overstates annual inflation by 1.1% (Boskin et al. 1996). That estimated CPI bias has not gotten smaller with time. It is now up to 1.5%, even 2%.

One of the rationales for the inflation target of the Reserve Bank of New Zealand of 0-2% was the 2% was to account for the consumer price index was biased upwards. Targeting 0% would lead to mild deflation when inflation was properly measured.

The main biases in the consumer price index everywhere come from how to handle changes in the quality of goods and services and how to deal with completely new goods and services.

I thought I might see what happened if I took this one and a half percentage point annual bias in the CPI estimated for the USA and adjusted the New Zealand CPI inflation rates available at the Reserve Bank of New Zealand’s website over the last 20 years or so with this number.

If these consumer price index bias adjustments are correct, and they are roughly correct, inflation came to a dead stop in New Zealand after the global financial crisis in 2008, spiked again, and then moved into deflation in 2012. If anything, there’s been a mixture of price stability and the deflation since 2012.

People get quite hot and bothered with deflation. The New Zealand economy has been in a deflationary phase since the beginning of 2012 but it is recently grown so quickly that it is referred to in the media as the rock-star economy.

Breathless journalism aside , fears of inflation are just a legacy of the great depression in the 1930s. The only depression where deflation was accompanied by mass unemployment was the Great Depression. Mild deflation with good growth is a common phenomena as Atkinson and Kehoe found:

Are deflation and depression empirically linked? No, concludes a broad historical study of inflation and real output growth rates. Deflation and depression do seem to have been linked during the 1930s. But in the rest of the data for 17 countries and more than 100 years, there is virtually no evidence of such a link.