Yes, Inflation/Deflation is Hard to Measure

One of the hardest concepts for Principles students, politicians and pundits, oh heck, just about everyone to fully grasp is inflation.  A big part of the reason is because inflation is an abstract concept that is not directly measurable.  We can conceive of it, but we can’t measure it.  I’m no physicist (and open to correction) but it strikes me that it’s a bit on par with “momentum” or “latent energy” in physics.   We don’t have direct-measuring energy-o-meters.  We measure the effects and infer the energy.  Inflation is similar.  We can conceive of a generalized, across-the-economy, sustained trend pushing all/most prices upward such that the unit of money is losing real value in general terms.  Inflation is the sustained push behind all prices. We can’t measure that directly. But we can measure the effect it has: rising prices. The problem comes in that not all prices will be rising at the same time or by the same amount.  Further, during any time period, at least part of the change in price for any good is it’s change in real price relative to all other goods (supply and demand as taught in micro).

We try to deal with this measurement issue by creating a price index – an index that tracks the changes in shopping list of goods over time.  But any price index is a just a subset of all the prices.  Even the Billion Price Project index at MIT admittedly misses most services and lots of consumer goods that aren’t available online.  Price indices are very imperfect beasts.  They have many faults, not the least of them being that they often tend to be volatile in nature.  Since we’re looking for an estimate of inflation which means sustained increases, we need to massage the data further by creating some kind of “core inflation” measure or “trimmed means” type price index.  I’ll explain those some other time.

What prompted today’s post is an article in Bloomberg and a post by Krugman about it.  Together they illustrate one of the reasons so many people want to believe we have greater inflation than we really do.  Companies like to disguise price changes.  They don’t want to be known that prices could be cut in response to demand. Example: auto company offers $2000 rebate on $20,000 car but won’t cut price by 10%, or a firm offers a “value meal”, or they offer a freebie bundled product.  Similarly they often disguise price increases by reducing sizes or portions or by changing the financing.  From Krugman:

Good article in Bloomberg:

Procter & Gamble Co.’s failure to raise the price of Cascade dishwashing soap shows why investors are buying Treasuries at the lowest yields in history, giving the Federal Reserve more scope to boost the economy.

The world’s largest consumer-products company rolled back prices after an 8 percent increase lost the firm 7 percentage points of market share. Kimberly-Clark Corp. (KMB) started offering coupons on Huggies after resistance to the diapers’ cost. Darden Restaurants Inc. (DRI) raised prices at less than the inflation rate as patrons order more of Olive Garden’s discounted stuffed rigatoni than it anticipated.

This is basic economics; prices tend to fall, or at least slow their rise, when there is vast excess capacity and weak demand.

As both the article and Krugman’s excerpt show, we’re closer to deflation than most people realize.  They don’t see the failed attempts to raise prices.  They don’t see the shifts in portions or increase in coupons that reduce effective prices.  What they do see and remember is the $.50 increase in a loaf of bread or the $.70 increase in a gallon of gas.  But even with the gas, they selectively remember the $.70 price increase in summer, but forget the $.75 price drop in autumn.  Inflation and deflation are tricky things to measure.


Inflation vs. The Cost of Living

We are now seeing a disconnect between how the public and policymakers/central banks perceive what each calls “inflation”.  The public at large, encouraged by talk from the hard-money gold crowd, are encouraged to see “inflation” whenever certain key prices go up.  Recently we’ve seen gasoline and food prices go up, and along with these price increases more people are worrying about “inflation”.   In reality, they are worried that the “cost of living” is going up.  Rises in the cost of living is not inflation.

Dennis Lockhart of the Atlanta Federal Reserve Bank gave an excellent explanation of the differences between “inflation” and “a rise in the cost of living” in a recent speech.  It is well worth reading in it’s entireity, particularly for any student of macro. Here’s an excerpt (emphasis is mine) of his key points – he explains each in greater detail:

the term “inflation” is misused in describing rising prices in narrow expenditure categories (for example, food inflation). Nonetheless, recent price news has encroached on the public consciousness with the effect that any price rise of an important consumption item is often taken as signaling inflation.

I think it would be helpful, therefore, to remind ourselves of three basic points about inflation and a central bank’s obligation to deliver price stability. They are

First: The rate of inflation encompasses all prices. It is the practical equivalent of the weakening of the domestic purchasing power of our money.

Second: Inflation is to be distinguished from the cost of living. While central banks, and only central banks, can control the domestic purchasing power of our money, central banks are largely powerless to prevent fluctuations in the cost of living.

Third: The primary economic cost of inflation is that it increases the risk associated with long term planning and decision making.

Let me elaborate on these points….

Lockhart goes on to explain some of the difficulties in monitoring (not really measuring) inflation prospects:

To achieve price stability, policymakers must detect inflation in its early stages before it is firmly established, especially in the psychology of consumers and businesses. This early detection is a challenge because inflation is not easily measured in the short term with any precision. No single price statistic enjoys a sufficient vantage point from which to assess inflation in the short term. With imperfect tools, inflation is more easily monitored than precisely measured.

Almost exactly 100 years ago, the economist Irving Fisher, who laid out many of the foundational ideas about money and inflation, likened measuring inflation or the purchasing power of money to tracking a swarm of bees. The swarm is going in a certain direction, while the bees have their own individual movements within the swarm…

Lockhart summarizes with (again emphasis is mine):

Notwithstanding the energy-driven jump in prices in December, underlying inflation is currently below the level that I would define as price stability. My current projection shows underlying inflation gradually rising over the next few years, putting us back into a range consistent with the 2 percent target by 2013. Key to the realization of this inflation forecast is that inflation expectations of the public remain well anchored. And for this to happen, the public has to have a good appreciation of what the central bank is trying to achieve and have adequate faith that we will achieve it.

In these remarks I have made a distinction between rising prices and a rising cost of living versus inflation. It’s a fair question—is this a distinction without a practical difference? Not at all. The distinction is real and important for all of us to grasp. The distinction ought not to be lost on the general public because to understand the intent of current policy, to form reasonable expectations, and to make sound decisions for the long term, the attention should be mostly on the full picture of inflation and the long-term purchasing power of our money. As a policymaker, I watch prices—that is, the behavior of highly evident and prominent prices we all take note of. I am also interested in movements in the cost of living that the great majority of households experience. But I am focused most intently on broad inflation because I believe long-term stable prices to be fundamental to a healthy and growing economy. For the moment, inflation, properly defined, is tame, in my view. And the rise of individual prices does not signal incipient inflation.

Excellent points.