cryptocurrency

Small deviations can have large consequences.

pnrj core principles, critique of neoclassical economics, market failure , , , , , ,

Jun 26 JDN 2459787

A common rejoinder that behavioral economists get from neoclassical economists is that most people are mostly rational most of the time, so what’s the big deal? If humans are 90% rational, why worry so much about the other 10%?

Well, it turns out that small deviations from rationality can have surprisingly large consequences. Let’s consider an example.

Suppose we have a market for some asset. Without even trying to veil my ulterior motive, let’s make that asset Bitcoin. Its fundamental value is of course $0; it’s not backed by anything (not even taxes or a central bank), it has no particular uses that aren’t already better served by existing methods, and it’s not even scalable.

Now, suppose that 99% of the population rationally recognizes that the fundamental value of the asset is indeed $0. But 1% of the population doesn’t; they irrationally believe that the asset is worth $20,000. What will the price of that asset be, in equilibrium?

If you assume that the majority will prevail, it should be $0. If you did some kind of weighted average, you’d think maybe its price will be something positive but relatively small, like $200. But is this actually the price it will take on?

Consider someone who currently owns 1 unit of the asset, and recognizes that it is fundamentally worthless. What should they do? Well, if they also know that there are people out there who believe it is worth $20,000, the answer is obvious: They should sell it to those people. Indeed, they should sell it for something quite close to $20,000 if they can.

Now, suppose they don’t already own the asset, but are considering whether or not to buy it. They know it’s worthless, but they also know that there are people who will buy it for close to $20,000. Here’s the kicker: This is a reason for them to buy it at anything meaningfully less than $20,000.

Suppose, for instance, they could buy it for $10,000. Spending $10,000 to buy something you know is worthless seems like a terribly irrational thing to do. But it isn’t irrational, if you also know that somewhere out there is someone who will pay $20,000 for that same asset and you have a reasonable chance of finding that person and selling it to them.

The equilibrium outcome, then, is that the price of the asset will be almost $20,000! Even though 99% of the population recognizes that this asset is worthless, the fact that 1% of people believe it’s worth as much as a car will result in it selling at that price. Thus, even a slight deviation from a perfectly-rational population can result in a market that is radically at odds with reality.

And it gets worse! Suppose that in fact everyone knows that the asset is worthless, but most people think that there is some small portion of the population who believes the asset has value. Then, it will still be priced at that value in equilibrium, as people trade it back and forth searching in vain for the person who really wants it! (This is called the Greater Fool theory.)

That is, the price of an asset in a free market—even in a market where most people are mostly rational most of the time—will in fact be determined by the highest price anyone believes that anyone else thinks it has. And this is true of essentially any asset market—any market where people are buying something, not to use it, but to sell it to someone else.

Of course, beliefs—and particularly beliefs about beliefs—can very easily change, so that equilibrium price could move in any direction basically without warning.

Suddenly, the cycle of bubble and crash, boom and bust, doesn’t seem so surprising does it? The wonder is that prices ever become stable at all.


Then again, do they? Last I checked, the only prices that were remotely stable were for goods like apples and cars and televisions, goods that are bought and sold to be consumed. (Or national currencies managed by competent central banks, whose entire job involves doing whatever it takes to keep those prices stable.) For pretty much everything else—and certainly any purely financial asset that isn’t a national currency—prices are indeed precisely as wildly unpredictable and utterly irrational as this model would predict.

So much for the Efficient Market Hypothesis? Sadly I doubt that the people who still believe this nonsense will be convinced.

The importance of encryption

pnrj computer science , , , , , ,

Feb 6 JDN 2459617

In last week’s post I told you of the compounding failures of cryptocurrency, which largely follow from the fact that it is very bad at being, well, currency. It doesn’t have a steady, predictable value, it isn’t easy to make payments with, and it isn’t accepted for most purchases.

But I realized that I haven’t ever gotten around to explaining anything about the crypto side of things—just what is encryption, and why does it matter?

At its core, encryption is any technique designed to disguise information so that it can be seen only by its intended viewers. Humans have been using some form of encryption since shortly after we invented writing—though, like any technology, our encryption has greatly improved over time.

Encryption involves converting a plaintext, the information you want to keep secret, into a ciphertext, a disguised form, using a key that is kept secret and can be used to convert the ciphertext back into plaintext. Decryption is the opposite process, extracting the plaintext from the ciphertext.

Some of the first forms of encryption were simple substitution ciphers: Have a set of rules that substitutes different letters for the original letters, such as “A becomes D, B becomes Q” and so on. This works pretty well, actually; but if each letter in the ciphertext always corresponds to the same letter in the plaintext, then you can look for patterns that would show up in text. For instance, E is usually the most common letter, so if you see a lot of three-letter sequences like BFP and P is a really common letter, odds are good that BFP is really THE and so you can guess that B=T, F=H, P=E.

More sophisticated ciphers tried to solve this problem by changing the substitution pattern as they go. The Enigma used by Nazi Germany was essentially this: It had a complex electrical and mechanical apparatus dedicated to changing the substitution rules with each key-press, in a manner that would be unpredictable to an outside observer but could be readily reproduced by using another Enigma machine. (Of course, it wasn’t actually as secure as they thought.)

For most of history, people have used what’s called private-key encryption, where there is a single key using for both encryption and decryption. In that case, you need to keep the key secret: If someone were to get their hands on it, they could easily decrypt all of your messages.

This is a problem, because with private-key encryption, you need to give the key to the person you want to read the message. And if there is a safe way to send the key, well… why couldn’t you send the message that way?

In the late 20th century mathematicians figured out an alternative, public-key encryption, which uses two keys: A private key, used to decrypt, and a new, public key, which can be used to encrypt. The public key is called “public” because you don’t need to keep it secret. You can hand it out to anyone, and they can encrypt messages with it. Those messages will be readable by you and you alone—for only you have the private key.

With most methods of public-key encryption, senders can even use their private key to prove to you that they are the person who sent the message, known as authentication. They encrypt it using their private key and your public key, and then you decrypt it using their public key and your private key.

This is great! It means that anyone can send messages to anyone else, and everyone will know not only that their information is safe, but also who it came from. You never have to transmit the private keys at all. Problem solved.


We now use public-key encryption for all sorts of things, particularly online: Online shopping, online banking, online tax filing. It’s not hard to imagine how catastrophic it could be if all of these forms of encryption were to suddenly fail.

In next week’s post, I’m going to talk about why I’m worried that something like that could one day happen, and what we might do in order to make sure it doesn’t. Stay tuned.

Cryptocurrency and its failures

pnrj core principles, current events, ethics, financial advice, financial fraud, futurism, inequality, market failure, politics, public policy , , , , , ,

Jan 30 JDN 2459620

It started out as a neat idea, though very much a solution in search of a problem. Using encryption, could we decentralize currency and eliminate the need for a central bank?

Well, it’s been a few years now, and we have now seen how well that went. Bitcoin recently crashed, but it has always been astonishingly volatile. As a speculative asset, such volatility is often tolerable—for many, even profitable. But as a currency, it is completely unbearable. People need to know that their money will be a store of value and a medium of exchange—and something that changes price one minute to the next is neither.

Some of cryptocurrency’s failures have been hilarious, like the ill-fated island called [yes, really] “Cryptoland”, which crashed and burned when they couldn’t find any investors to help them buy the island.

Others have been darkly comic, but tragic in their human consequences. Chief among these was the failed attempt by El Salvador to make Bitcoin an official currency.

At the time, President Bukele justified it by an economically baffling argument: Total value of all Bitcoin in the world is $680 billion, therefore if even 1% gets invested in El Salvador, GDP will increase by $6.8 billion, which is 25%!

First of all, that would only happen if 1% of all Bitcoin were invested in El Salvador each year—otherwise you’re looking at a one-time injection of money, not an increase in GDP.

But more importantly, this is like saying that the total US dollar supply is $6 trillion, (that’s physically cash; the actual money supply is considerably larger) so maybe by dollarizing your economy you can get 1% of that—$60 billion, baby! No, that’s not how any of this works. Dollarizing could still be a good idea (though it didn’t go all that well in El Salvador), but it won’t give you some kind of share in the US economy. You can’t collect dividends on US GDP.

It’s actually good how El Salvador’s experiment in bitcoin failed: Nobody bought into it in the first place. They couldn’t convince people to buy government assets that were backed by Bitcoin (perhaps because the assets were a strictly worse deal than just, er, buying Bitcoin). So the human cost of this idiotic experiment should be relatively minimal: It’s not like people are losing their homes over this.

That is, unless President Bukele doubles down, which he now appears to be doing. Even people who are big fans of cryptocurrency are unimpressed with El Salvador’s approach to it.

It would be one thing if there were some stable cryptocurrency that one could try pegging one’s national currency to, but there isn’t. Even so-called stablecoins are generally pegged to… regular currencies, typically the US dollar but also sometimes the Euro or a few other currencies. (I’ve seen the Australian Dollar and the Swiss Franc, but oddly enough, not the Pound Sterling.)

Or a country could try issuing its own cryptocurrency, as an all-digital currency instead of one that is partly paper. It’s not totally clear to me what advantages this would have over the current system (in which most of the money supply is bank deposits, i.e. already digital), but it would at least preserve the key advantage of having a central bank that can regulate your money supply.

But no, President Bukele decided to take an already-existing cryptocurrency, backed by nothing but the whims of the market, and make it legal tender. Somehow he missed the fact that a currency which rises and falls by 10% in a single day is generally considered bad.

Why? Is he just an idiot? I mean, maybe, though Bukele’s approval rating is astonishingly high. (And El Salvador is… mostly democratic. Unlike, say, Putin’s, I think these approval ratings are basically real.) But that’s not the only reason. My guess is that he was gripped by the same FOMO that has gripped everyone else who evangelizes for Bitcoin. The allure of easy money is often irresistible.

Consider President Bukele’s position. You’re governing a poor, war-torn country which has had economic problems of various types since its founding. When the national currency collapsed a generation ago, the country was put on the US dollar, but that didn’t solve the problem. So you’re looking for a better solution to the monetary doldrums your country has been in for decades.

You hear about a fancy new monetary technology, “cryptocurrency”, which has all the tech people really excited and seems to be making tons of money. You don’t understand a thing about it—hardly anyone seems to, in fact—but you know that people with a lot of insider knowledge of technology and finance are really invested in it, so it seems like there must be something good here. So, you decide to launch a program that will convert your country’s currency from the US dollar to one of these new cryptocurrencies—and you pick the most famous one, which is also extremely valuable, Bitcoin.

Could cryptocurrencies be the future of money, you wonder? Could this be the way to save your country’s economy?

Despite all the evidence that had already accumulated that cryptocurrency wasn’t working, I can understand why Bukele would be tempted by that dream. Just as we’d all like to get free money without having to work, he wanted to save his country’s economy without having to implement costly and unpopular reforms.

But there is no easy money. Not really. Some people get lucky; but they ultimately benefit from other people’s hard work.

The lesson here is deeper than cryptocurrency. Yes, clearly, it was a dumb idea to try to make Bitcoin a national currency, and it will get even dumber if Bukele really does double down on it. But more than that, we must all resist the lure of easy money. If it sounds too good to be true, it probably is.

Why is cryptocurrency popular?

pnrj financial advice, financial fraud, futurism, heuristics and biases, market failure, public policy , , , , , , , , , , , , ,

May 30 JDN 2459365

At the time of writing, the price of most cryptocurrencies has crashed, likely due to a ban on conventional banks using cryptocurrency in China (though perhaps also due to Elon Musk personally refusing to accept Bitcoin at his businesses). But for all I know by the time this post goes live the price will surge again. Or maybe they’ll crash even further. Who knows? The prices of popular cryptocurrencies have been extremely volatile.

This post isn’t really about the fluctuations of cryptocurrency prices. It’s about something a bit deeper: Why are people willing to put money into cryptocurrencies at all?

The comparison is often made to fiat currency: “Bitcoin isn’t backed by anything, but neither is the US dollar.”

But the US dollar is backed by something: It’s backed by the US government. Yes, it’s not tradeable for gold at a fixed price, but so what? You can use it to pay taxes. The government requires it to be legal tender for all debts. There are certain guaranteed exchange rights built into the US dollar, which underpin the value that the dollar takes on in other exchanges. Moreover, the US Federal Reserve carefully manages the supply of US dollars so as to keep their value roughly constant.

Bitcoin does not have this (nor does Dogecoin, or Etherium, or any of the other hundreds of lesser-known cryptocurrencies). There is no central bank. There is no government making them legal tender for any debts at all, let alone all of them. Nobody collects taxes in Bitcoin.

And so, because its value is untethered, Bitcoin’s price rises and falls, often in huge jumps, more or less randomly. If you look all the way back to when it was introduced, Bitcoin does seem to have an overall upward price trend, but this honestly seems like a statistical inevitability: If you start out being worthless, the only way your price can change is upward. While some people have become quite rich by buying into Bitcoin early on, there’s no particular reason to think that it will rise in value from here on out.

Nor does Bitcoin have any intrinsic value. You can’t eat it, or build things out of it, or use it for scientific research. It won’t even entertain you (unless you have a very weird sense of entertainment). Bitcoin doesn’t even have “intrinsic value” the way gold does (which is honestly an abuse of the term, since gold isn’t actually especially useful): It isn’t innately scarce. It was made scarce by its design: Through the blockchain, a clever application of encryption technology, it was made difficult to generate new Bitcoins (called “mining”) in an exponentially increasing way. But the decision of what encryption algorithm to use was utterly arbitrary. Bitcoin mining could just as well have been made a thousand times easier or a thousand times harder. They seem to have hit a sweet spot where they made it just hard enough that it make Bitcoin seem scarce while still making it feel feasible to get.

We could actually make a cryptocurrency that does something useful, by tying its mining to a genuinely valuable pursuit, like analyzing scientific data or proving mathematical theorems. Perhaps I should suggest a partnership with Folding@Home to make FoldCoin, the crypto coin you mine by folding proteins. There are some technical details there that would be a bit tricky, but I think it would probably be feasible. And then at least all this computing power would accomplish something, and the money people make would be to compensate them for their contribution.

But Bitcoin is not useful. No institution exists to stabilize its value. It constantly rises and falls in price. Why do people buy it?

In a word, FOMO. The fear of missing out. People buy Bitcoin because they see that a handful of other people have become rich by buying and selling Bitcoin. Bitcoin symbolizes financial freedom: The chance to become financially secure without having to participate any longer in our (utterly broken) labor market.

In this, volatility is not a bug but a feature: A stable currency won’t change much in value, so you’d only buy into it because you plan on spending it. But an unstable currency, now, there you might manage to get lucky speculating on its value and get rich quick for nothing. Or, more likely, you’ll end up poorer. You really have no way of knowing.

That makes cryptocurrency fundamentally like gambling. A few people make a lot of money playing poker, too; but most people who play poker lose money. Indeed, those people who get rich are only able to get rich because other people lose money. The game is zero-sum—and likewise so is cryptocurrency.

Note that this is not how the stock market works, or at least not how it’s supposed to work (sometimes maybe). When you buy a stock, you are buying a share of the profits of a corporation—a real, actual corporation that produces and sells goods or services. You’re (ostensibly) supplying capital to fund the operations of that corporation, so that they might make and sell more goods in order to earn more profit, which they will then share with you.

Likewise when you buy a bond: You are lending money to an institution (usually a corporation or a government) that intends to use that money to do something—some real actual thing in the world, like building a factory or a bridge. They are willing to pay interest on that debt in order to get the money now rather than having to wait.

Initial Coin Offerings were supposed to be away to turn cryptocurrency into a genuine investment, but at least in their current virtually unregulated form, they are basically indistinguishable from a Ponzi scheme. Unless the value of the coin is somehow tied to actual ownership of the corporation or shares of its profits (the way stocks are), there’s nothing to ensure that the people who buy into the coin will actually receive anything in return for the capital they invest. There’s really very little stopping a startup from running an ICO, receiving a bunch of cash, and then absconding to the Cayman Islands. If they made it really obvious like that, maybe a lawsuit would succeed; but as long as they can create even the appearance of a good-faith investment—or even actually make their business profitable!—there’s nothing forcing them to pay a cent to the owners of their cryptocurrency.

The really frustrating thing for me about all this is that, sometimes, it works. There actually are now thousands of people who made decisions that by any objective standard were irrational and irresponsible, and then came out of it millionaires. It’s much like the lottery: Playing the lottery is clearly and objectively a bad idea, but every once in awhile it will work and make you massively better off.

It’s like I said in a post about a year ago: Glorifying superstars glorifies risk. When a handful of people can massively succeed by making a decision, that makes a lot of other people think that it was a good decision. But quite often, it wasn’t a good decision at all; they just got spectacularly lucky.

I can’t exactly say you shouldn’t buy any cryptocurrency. It probably has better odds than playing poker or blackjack, and it certainly has better odds than playing the lottery. But what I can say is this: It’s about odds. It’s gambling. It may be relatively smart gambling (poker and blackjack are certainly a better idea than roulette or slot machines), with relatively good odds—but it’s still gambling. It’s a zero-sum high-risk exchange of money that makes a few people rich and lots of other people poorer.

With that in mind, don’t put any money into cryptocurrency that you couldn’t afford to lose at a blackjack table. If you’re looking for something to seriously invest your savings in, the answer remains the same: Stocks. All the stocks.

I doubt this particular crash will be the end for cryptocurrency, but I do think it may be the beginning of the end. I think people are finally beginning to realize that cryptocurrencies are really not the spectacular innovation that they were hyped to be, but more like a high-tech iteration of the ancient art of the Ponzi scheme. Maybe blockchain technology will ultimately prove useful for something—hey, maybe we should actually try making FoldCoin. But the future of money remains much as it has been for quite some time: Fiat currency managed by central banks.