The Growing Economic Sandpile

August 31, 2018

“How did you go bankrupt?” 
“Two ways. Gradually, then suddenly.”

―Ernest Hemingway, The Sun Also Rises

As you may have noticed, I’ve been in a pensive mood lately. I’m re-thinking a lot of things as I process economic developments, personal issues, and the clock ticking as I reach birthday number 69 in a few weeks. Many good things are happening but with them comes change.

Change will be today’s topic. Below I’m reproducing part of a letter I originally wrote in December 2007 and have referred to several times. It is the single most-read letter I have written and the most commented-on, too. I consider it, in some ways, my most important letter. If you’ve read it before, you should read it again. I have updated it a little bit, but the principles are just as timeless as ever. And for the time conscious, we have shortened it a bit and at the end, I try to apply those principles to present economic times.

Change happens quickly and often, unpredictably. And as we will see, the unpredictable part is actually a mathematical principle. As in the Hemingway quote above, not just bankruptcy but change also happens slowly and then seemingly all at once. It’s time passing without change that causes the worst problems, including some historic economic catastrophes. It turns out we shouldn’t just accept change; we actually require it.

I’ll be quoting from a very important book by Mark Buchanan called Ubiquity, Why Catastrophes Happen. I HIGHLY recommend it if you, like me, are trying to understand the complexity of the markets. Not directly about investing, although he touches on it, the book is about chaos theory, complexity theory, and critical states. It is written so any layman can understand—no equations, just easy-to-grasp, well-written stories and analogies.

Here’s what I wrote in 2007, with new comments and thoughts.

Ubiquity, Complexity Theory, and Sandpiles

We have all had the fun as kids of going to the beach and playing in the sand. Remember taking your plastic bucket and making sandpiles? Slowly pouring the sand into ever bigger piles, until one side of the pile starts to collapse?

Imagine, Buchanan says, dropping one grain of sand after another onto a table. A pile soon develops. Eventually, just one grain starts an avalanche. Most of the time, it’s a small one. But sometimes, it builds up and it seems like one whole side of the pile slides down to the bottom.

Well, in 1987 three physicists named Per Bak, Chao Tang, and Kurt Wiesenfeld began to play the sandpile game in their lab at Brookhaven National Laboratory in New York. Actually piling up one grain of sand at a time is a slow process, so they wrote a computer program to do it. Not as much fun but a whole lot faster. Not that they really cared about sandpiles. They were more interested in what are called nonequilibrium systems.

They learned some interesting things. What is the typical size of an avalanche? After a huge number of tests with millions of grains of sand, they found out there is no typical number:

Some involved a single grain; others, ten, a hundred, or a thousand. Still others were pile-wide cataclysms involving millions that brought nearly the whole mountain down. At any time, literally anything, it seemed, might be just about to occur.

The pile was indeed completely chaotic in its unpredictability. Now, let’s read this next paragraph slowly. It is important, as it creates a mental image that helps me understand the organization of the financial markets and the world economy. (emphasis mine)

To find out why [such unpredictability] should show up in their sandpile game, Bak and colleagues next played a trick with their computer. Imagine peering down on the pile from above and coloring it in according to its steepness. Where it is relatively flat and stable, color it green; where steep and, in avalanche terms, “ready to go,” color it red. What do you see? They found that at the outset, the pile looked mostly green, but that, as the pile grew, the green became infiltrated with ever more red. With more grains, the scattering of red danger spots grew until a dense skeleton of instability ran through the pile. Here then was a clue to its peculiar behavior: a grain falling on a red spot can, by domino-like action, cause sliding at other nearby red spots. If the red network was sparse, and all trouble spots were well isolated one from the other, then a single grain could have only limited repercussions. But when the red spots come to riddle the pile, the consequences of the next grain become fiendishly unpredictable. It might trigger only a few tumblings, or it might instead set off a cataclysmic chain reaction involving millions. The sandpile seemed to have configured itself into a hypersensitive and peculiarly unstable condition in which the next falling grain could trigger a response of any size whatsoever.

Something only a math nerd could love? Scientists refer to this as a critical state. The term critical state can mean the point at which water would go to ice or steam, or the moment that critical mass induces a nuclear reaction, etc. It is the point at which something triggers a change in the basic nature or character of the object or group. Thus, (and very casually, for all you physicists) we refer to something being in a critical state (or use the term critical mass) when there is the opportunity for significant change.

But to physicists, [the critical state] has always been seen as a kind of theoretical freak and sideshow, a devilishly unstable and unusual condition that arises only under the most exceptional circumstances [in highly controlled experiments]... . In the sandpile game, however, a critical state seemed to arise naturally through the mindless sprinkling of grains.

Thus, they asked themselves, could this phenomenon show up elsewhere? In the earth’s crust, triggering earthquakes; in wholesale changes in an ecosystem; or in a stock market crash? “Could the special organization of the critical state explain why the world at large seems so susceptible to unpredictable upheavals?” Buchanan asks. Could it help us understand not just earthquakes but why a cartoon in a third-rate paper in Denmark could cause worldwide riots?

Buchanan concludes in his opening chapter:

There are many subtleties and twists in the story... but the basic message, roughly speaking, is simple: The peculiar and exceptionally unstable organization of the critical state does indeed seem to be ubiquitous in our world. Researchers in the past few years have found its mathematical fingerprints in the workings of all the upheavals I’ve mentioned so far [earthquakes, eco-disasters, market crashes], as well as in the spreading of epidemics, the flaring of traffic jams, the patterns by which instructions trickle down from managers to workers in the office, and in many other things. At the heart of our story, then, lies the discovery that networks of things of all kinds—atoms, molecules, species, people, and even ideas—have a marked tendency to organize themselves along similar lines. On the basis of this insight, scientists are finally beginning to fathom what lies behind tumultuous events of all sorts, and to see patterns at work where they have never seen them before.

Fingers of Instability

So, what happens in our game?

[A]fter the pile evolves into a critical state, many grains rest just on the verge of tumbling, and these grains link up into “fingers of instability” of all possible lengths. While many are short, others slice through the pile from one end to the other. So, the chain reaction triggered by a single grain might lead to an avalanche of any size whatsoever, depending on whether that grain fell on a short, intermediate, or long finger of instability.

Now we come to a critical point in our discussion of the critical state. Read this next excerpt with the markets in mind (again, emphasis mine, and this is critical to our understanding of markets and change. Maybe you should read it two or three times.):

In this simplified setting of the sandpile, the power law also points to something else: the surprising conclusion that even the greatest of events have no special or exceptional causes. After all, every avalanche large or small starts out the same way, when a single grain falls and makes the pile just slightly too steep at one point. What makes one avalanche much larger than another has nothing to do with its original cause, and nothing to do with some special situation in the pile just before it starts. Rather, it has to do with the perpetually unstable organization of the critical state, which makes it always possible for the next grain to trigger an avalanche of any size.

Now, let’s couple this idea with a few other concepts. First, economist Dr. Hyman Minsky points out that stability leads to instability. The more comfortable we get with a given condition or trend, the longer it will persist, and then when the trend fails, the more dramatic the correction. The problem with long-term macroeconomic stability is that it tends to produce unstable financial arrangements. If we believe that tomorrow and next year will be the same as last week and last year, we are more willing to add debt or postpone savings in favor of current consumption. Thus, says Minsky, the longer the period of stability, the higher the potential risk for even greater instability when market participants must change their behavior.

Relating this to our sandpile, the longer a critical state builds up in an economy—or in other words, the more “fingers of instability” that are allowed to develop a connection to other fingers of instability—the greater the potential for a serious “avalanche.”

A second related concept is from game theory. The Nash equilibrium (named after John Nash, subject of the Oscar-winning movie A Beautiful Mind) is a kind of optimal strategy for games involving two or more players, whereby the players reach an outcome to mutual advantage. If there is a set of strategies for a game with the property that no player can benefit by changing his strategy while the other players keep their strategies unchanged, then that set of strategies and the corresponding payoffs constitute a Nash equilibrium.

(2018 sidebar: One of my concerns with President Trump initiating tariffs, even when other countries have higher tariffs, is the world had a kind of Nash equilibrium based on the current state of affairs. Trump was and is purposefully disturbing that equilibrium, and it was unclear at the beginning what would happen. It now looks like there is at least the potential for a new and better equilibrium. Brexit is another case where a Nash equilibrium had been reached and then was disturbed. Few trading systems use multiplayer game theory in their algorithms because it is devilishly hard for a program to see in advance where all those fingers of instability lie and what will trigger an event.)

A Stable Disequilibrium

So, we end up in a critical state of what Paul McCulley calls a “stable disequilibrium.” We have “players” of this game from all over the world tied inextricably together in a vast dance through investment, debt, derivatives, trade, globalization, international business, and finance. Each player works hard to maximize their personal outcome and to reduce their exposure to “fingers of instability.”

But the longer the game runs, asserts Minsky, the more likely it is to end in a violent “avalanche,” as the fingers of instability have more time to build, and eventually the state of stable disequilibrium goes critical on us.

Go back to 1997. Thailand began to experience trouble. The debt explosion in Asia began to unravel. Russia was defaulting on its bonds. (Astounding. Was it less than ten years ago? Now Russia is awash in capital. Who could have anticipated such a dramatic turn of events?) Things on the periphery, small fingers of instability, began to impinge on fault lines in the major world economies.

Something that had not been seen before happened. The historically sound and mathematically logical relationship between 29- and 30-year bonds broke down. Then country after country suddenly and inexplicably saw that relationship in their bonds begin to correlate, an unheard-of event. A diversified pool of debt was suddenly no longer diversified. The fingers of instability reached into Long Term Capital Management and nearly brought the financial world to its knees.

And now, a different set of fingers of instability are creating an even worse crisis in the credit markets.

Sandpile 2018

All right, back to the present. When I originally wrote this letter, it was 2007 and the fingers of instability had not created the Great Recession. You could certainly see red dots in the sandpile, most notably subprime debt, but there were literally hundreds of dots scattered throughout the world economy, most of them innocuous until they weren’t. And then the scramble for liquidity began, except the liquidity wasn’t there, and well, you know the rest of the story.

This should be even more concerning if you think about my recent Train Wreck series (recap here). We are adding sand to not just one inevitably-collapsing sandpile, but dozens and maybe hundreds of them. They will not keep growing forever.

I explained in Part 1 of that series, Credit-Driven Train Wreck, how a liquidity crisis will probably set off the chain of events that end in the Great Reset. Which particular sandpile will fall first? It could be many, but I think high-yield corporate debt is the most likely. Millions of investors think they can collect those juicy yields and then be able to sell when trouble appears.

They’re partly right. They will be able to sell… but well below the prices they expect.

Yesterday, I did an interview with the extraordinarily astute Howard Gold of MarketWatch. We discussed the connectedness of so many global markets and how the debt crisis, unfunded pension liabilities, and government promises all over the world seemingly keep mounting, yet markets go up more.

I think the mother of all Minsky moments is building. It will not be an instant sandpile collapse, but instead take years because we have $500 trillion of debt to work through. Remember, that debt just can’t be pooped away. It is both money somebody owes and an asset on somebody else’s balance sheet. If you are retired, your pension and healthcare benefits are part of your net worth. They are assets on your balance sheet that you count on to cover future spending. We can’t just take that away without huge consequences to culture and society.

But the fingers of instability, the total credit system, are seemingly growing with more red sand dots every month. All are inextricably linked. One day, another Thailand or Russia or something else (it makes no difference which) will start the cascade.

Remember, very astute people saw the subprime crisis and made a lot of money shorting that market. I saw it coming but didn’t know how to trade it. I guarantee you, I’m paying attention now to who can profit from the next credit crisis. Maybe I’ll be successful and maybe I won’t, but just once, I would like to be on the right side of a crisis.

No More Business Cycles

One last comment that I picked up over the years. My friend Peter Boockvar actually crystallized this thought a few months ago, but I think I’m going to make it part of my own liturgy: We no longer have business cycles, we have credit cycles. Central banks and governments, not to mention investment banks and investors, are all using credit in formerly unbelievable numbers and ways, and I am here to shout that the world is becoming one massive finger of instability.

Going back to that 1987 mathematical experiment, the simple fact is there are green sand dots all over the world. They represent stability in the global system, which is allowing the fingers of instability to build up in a potentially deadlier way than we have ever seen before.

We take comfort from the stability we see around us. Unemployment rates are low. Interest rates, while rising somewhat on the short end, are still historically very low. Corporate profits are up. We are greeted every day with some amazing new technological innovation that changes everything in some industry. Living standards keep rising.

And yet, Minsky tells us stability breeds instability. That sandpile program, as simple as it seems now, shows that the longer the stability lasts, with the fingers of instability connecting in hidden and unknown ways, the greater the avalanche will be.

I suggest you read at least the first half of Nassim Nicholas Taleb’s book, Antifragile. (He is also the author of the must-read books, Incerto: Fooled by Randomness and The Black Swan.) Here are three lessons that will show you what it means to be antifragile:

  1. Fragile items break under stress, antifragile items get better from it.
  1. In order for a system to be antifragile, most of its parts must be fragile.
  1. Antifragile systems work because they build extra capacity when put under stress.

This is a great way to explain the sandpile game in economic terms. Economic sandpiles that have many small avalanches never have large fingers of stability and massive avalanches. The more small, economically unpleasant events you allow to happen, the fewer large and eventually massive fingers of instability will build up.

The efforts by regulators and central bankers to create stable systems and prevent small losses actually create the large fingers of instability that bring down whole systems and spark global recessions. And increasingly, it is the unfunded liability of government promises that will be the most massively unstable finger.

In that crisis, things that should be totally unrelated all of a sudden become intertwined. The correlations of formerly unrelated asset classes all go to one at the absolute wrong time. Panic ensues, losses are taken. Government steps in trying to stem the tide, perhaps appropriately so, but eventually the markets have to clear.

There is a surprising but critically powerful thought in that computer model from 30 years ago: We cannot accurately predict when the avalanche will happen. You can miss out on all sorts of opportunities because you see lots of fingers of instability and ignore the base of stability. And then you can lose it all at once because you ignored the fingers of instability.

You need your portfolios to both participate and protect. Don’t blindly buy index funds and assume they will recover as they did in the past. This next avalanche is going to change the nature of recoveries as other market forces and new technologies change what makes an investment succeed. I cannot stress that enough. Do not get caught in a buy-and-hold, traditional 60/40 portfolio. Don’t walk away from it. Run away.

Cautious optimism is always the long-term winner. Always. But a buy-and-hold portfolio in today’s world is neither cautious nor optimistic. Hope is not a strategy. That’s precisely what a buy-and-hold portfolio is.

Up in the Air Travel Schedule and the Worst Football Game Ever

I technically have no actual flight plans until a November speaking engagement in Frankfurt—well, except for a day trip to Houston—but I know I will have to be all over the country, and probably somewhere in the UK, in the coming months. I really like to be more scheduled, but that’s just not the way the world is working right now.

Last week, Shane and I went to a pre-season Dallas Cowboys football game with new friends Howard Getson and his wife Jen, whom I met at Camp Kotok this summer. We had a great time but it may have been the worst football game I’ve ever seen. I actually wanted to stop the game out of pity, or at least go down on the field to introduce the players to each other.

I felt a bit like those football rookies when I first went to Rice University decades ago. I arrived there certain I would be the physicist to crack the secrets of the atom. After about six weeks, I re-thought that career choice, which was good because I would’ve been a mediocre scientist. Fortunately, I did have a way to turn a phrase, and I turned that into a career.

It’s kind of like the sandpile game. Identify the biggest avalanche in your personal career path, and you’re on your way. It may not be your first choice, but it’s what will give you the most pleasure because you’ll be doing what you do best. I’m not sure that was the case for some of those Cowboys players.

And with that, let me hit the send button and wish you a great week. If you’re in the US, Happy Labor Day!

Your in a bit of a philosophical mood analyst,

John Mauldin

Thoughts From The Frontline


Discuss This


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Sep. 1, 2018, 9:52 a.m.

What starts a bank run?  A sudden perception spreading like wild fire

When is the emperor seen to be without clothes?  When the innocent proclaim the obvious

I am terrified by the thought that this age of instant and universal information has the potential to upend the economic structure in a matter of days, with either real or false facts

Ernest M Kraus

Sep. 1, 2018, 7:10 a.m.

The angle of repose works with materials because there is no emotion. It does not work in economics because there is emotion.

James Corbett

Sep. 1, 2018, 4:41 a.m.

The central banks, particularly the Federal Reserve, have been central in allowing the sand to pile so high with their belief that they can actually manage an incredibly complex economy through their very limited knowledge of it. I believe that when the sand starts to avalanche both the Federal Reserve and Congress will ultimately lay much of the burden on the taxpayers as well as make things worse. Many people do not understand that FDR’s policies, rubber-stamped by Congress, as well as the Federal Reserve’s, made the Great Depression longer and deeper than it needed to be had it been allowed to run its natural course. The repercussions are still with us, for example, no longer have a gold-backed currency not to mention FDIC and Social Security.