8 May 2019 – There’s been a bit of noise in financial-media circles this week (as of this writing, but it’ll be last week when you get to read it) about Federal Reserve Chairman Jerome Powell’s talking up shifting the Fed’s focus to targeting something called “average inflation” and using words like “transient” and “symmetric” to describe this thinking. James Macintosh provided a nice layman-centric description of the pros and cons of this concept in his “Streetwise” column in Friday’s (5/3) The Wall Street Journal. (Sorry, folks, but this article is only available to WSJ subscribers, so the link above leads to a teaser that asks you to either sign in as a current subscriber or to become a new subscriber. And, you thought information was supposed to be distributed for free? Think again!)
I’m not going to rehash what Macintosh wrote, but attempt to show why this change makes sense. In fact, it’s not really a change at all, but an acknowledgement of what’s really been going on all the time.
We start with pointing out that what the Federal Reserve System is mandated to do is to control the U.S. economy. The operant word here is “control.” That means that to understand what the Fed does (and what it should do) requires a basic understanding of control theory.
Basic Control Theory
We’ll start with a thermostat.
A lot of people (I hesitate to say “most” because I’ve encountered so many counter examples – otherwise intelligent people who somehow don’t seem to get the point) understand how a thermostat works.
A thermostat is the poster child for basic automated control systems. It’s the “stone knives and bearskins” version of automated controls, and is the easiest for the layman to understand, so that’s where we’ll start. It’s also a good analog for what has passed for economic controls since the Fed was created in 1913.
Okay, the first thing to understand is the concept of a “set point.” That’s a “desired value” of some measurement that represents the thing you want to control. In the case of the thermostat, the measurement is room temperature (as read out from a thermometer) and the thing you’re trying to control is how comfortable the room air feels to you. In the case of the Fed, the thing you want to control is overall economic performance and the measurement folks decided was most useful is the inflation rate.
Currently, the set point for inflation is 2% per annum.
In the case of the thermostat in our condo, my wife and I have settled on 75º F. That’s a choice we’ve made based on the climate where we live (Southwestern Florida), our ages, and what we, through experience, have found to be most comfortable for us right now. When we lived in New England, we chose a different set point. Similarly, when we lived in Northern Arizona it was different as well.
The bottom line is: the set point is a matter of choice based on a whole raft of factors that we think are important to us and it varies from time to time.
The same goes for the Fed’s inflation set point. It’s a choice Fed governors make based on a whole raft of considerations that they think are important to the country right now. One of the reasons they meet every month is to review that target ‘cause they know that things change. What seems like a good idea in July, might not look so good in August.
Now, it’s important to recognize that the set point is a target. Like any target, you’re trying to hit it, but you don’t really expect to hit it exactly. You really expect that the value you get for your performance measurement will differ from your set point by some amount – by some error or what metrologists prefer to call “deviation.” We prefer deviation to the word error because it has less pejorative connotations. It’s a fact of life, not a bad thing.
When we add in the concept of time, we also introduce the concept of feedback. That is what control theorists call it when you take the results of your measurement and feed it back to your decision of what to do next.
What you do next to control whatever you’re trying to control depends, first, on the sign (positive or negative) of the deviation, and, in more sophisticated controls, it’s value or magnitude. In the case of the thermostat, if the deviation is positive (meaning the room is hotter than you want) you want to do something to cool it down. In the case of the economy, if inflation is too high you want to do something to reduce economic activity so you don’t get an economic bubble that’ll soon burst.
What confuses some presidents is the idea that rising economic activity isn’t always good. Presidents like boom times ‘cause they make people feel good – like a sugar high. Populist presidents typically fail to recognize (or care about the fact) that booms are invariably bubbles that burst disastrously. Just ask the people of Venezuela who watched their economy’s inflation rate suddenly shoot up to about a million(!) percent per annum.
Booms turn to busts in a heartbeat!
This is where we want to abandon the analogy with a thermostat and get a little more sophisticated.
A thermostat is a blunt instrument. What the thermostat automatically does next is like using a club. At best, a thermostat has two clubs to choose from: it can either fire up the furnace (to raise the room temperature in the event of a negative deviation) or kick in the air conditioner (in the event that the deviation is positive – too hot). That’s known as a binary digital control. It’s gives you a digital choice: up or down.
We leave the thermostat analogy because the Fed’s main tool for controlling the economy (the Fed-funds interest rate) is a lot more sophisticated. It’s what mathematicians call analog. That is, instead of providing a binary choice (to use the club or not), it lets you choose how much pressure you want to apply up or down.
Quantitative easing similarly provides analog control, so what I’m going to say below also applies to it.
Okay, the Fed’s control lever (Fed funds interest rate) is more like a brake pedal than a club. In a car, the harder you press the brake pedal, the more pressure you apply to make the car slow down. A little pressure makes the car slow down a little. A lot of pressure makes the car slow down a lot.
So, you can see why authoritarians like low interest rates. Autthoritarians generally have high-D personalities. As Personality Insights says: “They tend to know 2 speeds in life – zero and full throttle… mostly full throttle.”
They generally don’t have much use for brakes!
By the way, the thing governments have that corresponds to a gas pedal is deficit spending, but the correspondence isn’t exact and the Fed can’t control it, anyway. Since this article is about the Fed, we aren’t going to talk about it now.
When inflation’s moving too fast (above the set point) by a little, the Fed governors – being the feedback controller – decide to raise the Fed funds rate, which is analogous to pushing the brake pedal, by a little. If that doesn’t work, they push it a little harder. If inflation seems to be out of control, as it did in the 1970s, they push it as hard as they can, boosting interest rates way up and pulling way back on the economy.
Populist dictators, who generally don’t know what they’re doing, try to prevent their central banks (you can’t have an economy without having a central bank, even if you don’t know you have it) from raising interest rates soon enough or high enough to get inflation under control, which is why populist dictatorships generally end up with hyperinflation leading to economic collapse.
Populist Dictators Need Not Apply
This is why we don’t want the U.S. Federal Reserve Bank under political control. Politicians are not elected for their economic savvy, so we want Fed governors, who are supposed to have economic savvy, to make smart decisions based on their understanding of economic causes and effects, rather than dumb decisions based on political expediency.
Economists are mathematically sophisticated people. They may (or may not) be steeped in the theory of automated control systems, but they’re quite capable of understanding these basics and how they apply to controlling an economy.
Economics, of course, has been around as long as civilization. Hesiod (ca. 750 BCE) is sometimes considered “the first economist.” Contemporary economics traces back to the eighteenth century with Adam Smith. Control theory, on the other hand, has only been elucidated since the early 1950s. So, you don’t really need control theory to understand economics. It just makes it easier to see how the controls work.
To a veteran test and measurement maven like myself, the idea of thinking in terms of average inflation, instead of the observed inflation at some point in time – like right now – makes perfect sense. We know that every time you make a measurement of anything, you’re almost guaranteed to get a different value than you got the last time you measured it. That’s why we (scientists and engineers) always measure whatever we care about multiple times and pay attention to the average of the measurements instead of each measurement individually.
So, Fed governors starting to pay attention to average inflation strikes us as a duh! What else would you look at?
Similarly, using words like “transient” and “symmetric” make perfect sense because “transient” expresses the idea that things change faster than you can measure them and “symmetric” expresses the idea that measurement variations can be positive or negative – symmetric each side of the average.
These ideas all come from the mathematics of statistics. You’ve heard of “statistical significance” associated with polling data, or two polling results being within “statistical error.” The variations I’m talking about are the same thing. Variations between two values (like the average inflation and the target inflation) are statistically significant if they’re sufficiently outside the statistical error.
I’m not going to go into how you calculate a value for statistical error because it takes hours of yammering to teach it in statistics classes, and I just don’t have the space here. You wouldn’t want to read it right now, anyway. Suffice it to say that it’s a well-defined concept relating to how much variation you can expect in a given data set.
While the control theory I’ve been talking about applies especially to automated control systems, it applies equally to Federal Reserve System control of economic performance – if you put the Federal Open Market Committee (FOMC) in place of the control computer that makes decisions for the automated control system.
“So,” you ask, “why not put the Fed-funds rate under computer control?”.
The reason it would be unreasonable to fully automate the Fed’s actions is that we can’t duplicate the thinking process of the Fed governors in a computer program. The state of the art of economic models is just not good enough, yet. We still need the gut feelings of seasoned economists to make enough sense out of what goes on in the economy to figure out what to do next.
That, by the way, is why we don’t leave the decisions up to some hyperintelligent pandimensional being (named Trump). We need a panel of economists with diverse backgrounds and experiences – the FOMC – to have some hope of getting it right!