“Economics and finance are like going to the dog races,” my friend Desmond Lachman of the American Enterprise Institute is fond of saying. “Stand in the same place and the dogs will come around again.” So they will.

U.S. financial markets produced sequential bubbles – first in tech stocks in the 1990s and then in houses in the 2000s.

“What is the collateral for a home mortgage loan?” I like to ask audiences of mortgage lenders.  Of course, they say, “the house,” so I am pleased to tell them that is the wrong answer.  The correct answer is the price of the house.  My next question is, “How much can a price change?”  Ponder that.  The correct answer is that prices, having no independent, objective existence, can change a lot more than you think. They can go up a lot more than you think probable, and they can go down a lot more than you think possible. And they can do first one and then the other.

This is notably displayed by the asset price behavior in both the tech stock and housing bubbles.  As the dogs raced around again, they made a remarkably symmetrical round trip in prices.

Graph 1 shows the symmetrical round trip of the notorious “irrational exuberance” in dot-com equities, followed by unexuberance. It displays the NASDAQ stock index expressed in constant dollars.

graf 1

Now consider houses.  Graph 2 shows the Case-Shiller U.S. national house price index expressed in constant dollars.  Quite a similar pattern of going up a lot and then going down as much.

graf 2

The mortgage lending excesses essential to the housing bubble reflected, in part, a mania of politicians to drive up the U.S. homeownership rate. The pols discovered, so they thought, how to do this: make more bad loans—only they called them, “creative loans.” The homeownership rate did rise significantly—and then went back down to exactly where it was before. Another instructive symmetrical round trip, as shown in Graph 3.


The first symmetrical up and down played out in the course of three years, the second in 12 years, the third in two decades. Much longer patterns are possible. Graph 4 shows the amazing six-decade symmetry in U.S. long-term interest rates.

graf 4

Is there magic or determinism in this symmetry? Well, perhaps the persistence of underlying fundamental trends and the regression to them shows through, as does the reminder of how very much prices can change. In the fourth graph, we also see the dangerous power of fiat currency-issuing central banks to drive prices to extremes.

Unfortunately, graphs of the past do not tell us what is coming next, no matter how many of them economists and analysts may draw. But they do usefully remind us of the frequent vanity of human hopes and political schemes.

Image by Manfred Ruckszio

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