Do Bitcoins Violate a Fundamental Economic Law?

Want to buy a bitcoin?

If you click over to Mt. Gox, the most famous bitcoin exchange, one unit of the crypto-currency will set you back $145. But at Bitstamp you would pay only $129. (At time of writing; prices can change quickly.)

Mt. Gox traders are thus paying a 12% premium for their bitcoins.

That spread seems to violate a fundamental economic law. When transaction costs are low, identical items should trade at nearly identical prices. Otherwise, arbitrageurs would step in to buy cheap and sell dear until the price gap narrows.

But that isn’t happening.

The “law of one price” used to hold. Last fall and winter bitcoin prices at the two big exchanges typically differed by less than 2 percent, a reasonable range given exchange fees and the cost of money transfers.

(click to enlarge)

In April, however, the bitcoin market went haywire. After spiking to $266 on Mt. Gox, bitcoin prices cratered, falling as low as $54 just two days later. That volatility created large, but temporary spreads between prices on different exchanges (and made it difficult to measure spreads accurately).

When conditions calmed, spreads returned to normal. And then Mt. Gox’s troubles began.

On May 14 the U.S. government accused the exchange of operating an illegal money service business. The government seized $5 million that Mt. Gox held at Dwolla (an online payment processor) and Wells Fargo.

Fearing for their money, Mt. Gox customers converted their at-risk dollars into easy-to-withdraw bitcoins, and the Mt. Gox-Bitstamp spread spiked to 5%.

Spreads briefly normalized until Mt. Gox announced that it was suspending U.S. dollar withdrawals. Mt. Gox had become a Roach Motel (or, if you prefer, a Hotel California) for U.S. dollars. Traders could check their dollars in, but they couldn’t check them out.

Customers responded as you would expect. The spread spiked to 6%, as Mt. Gox traders again converted dollars into bitcoins. The spread briefly narrowed after Mt. Gox’s July 4 announcement of resumed dollar withdrawals. But spreads then spiked to record levels once Mt. Gox customers started reporting that withdrawals remained slow or nonexistent.

Mt. Gox prices are higher than on Bitstamp today because customers apparently can’t get their dollars out of Mt. Gox. So they pay extra for bitcoins. For those customers, a Mt. Gox bitcoin is different from one anywhere else. So the Mt. Gox price isn’t a clean measure of a bitcoin’s value. Instead, it measures the value of a bitcoin plus the desperation of Mt. Gox’s customers.

But that still leaves a puzzle. It makes sense that customers will pay a premium to get their money out. But who is willing to take the other side of the trade, selling bitcoins in return for “Mt. Gox dollars”?

As best as I can tell, those traders have stayed silent on the bitcoin chat boards. Perhaps they are newcomers who think they’ve found an arbitrage opportunity and don’t realize their dollars will be hard to withdraw. Or perhaps they believe that Mt. Gox will get its act together. (A more sinister take, raised on the boards, is that some preferred traders do have the ability to withdraw.) Whatever the case, they stand to make a tidy profit if they can get their dollars out, and sorely disappointed if they can’t.

Sources: For a quick explanation of bitcoin, try this introduction. For price data from numerous exchanges, visit bitcoin charts. My chart uses a 7-day moving average of spreads to smooth the volatility. The measured spread has at times been much higher, e.g., 40%+ on April 10, but that passed quickly.

Disclosure: I own 0.1 bitcoin.

About Donald Marron 294 Articles

Donald Marron is an economist in the Washington, DC area. He currently speaks, writes, and consults about economic, budget, and financial issues.

From 2002 to early 2009, he served in various senior positions in the White House and Congress including: * Member of the President’s Council of Economic Advisers (CEA) * Acting Director of the Congressional Budget Office (CBO) * Executive Director of Congress’s Joint Economic Committee (JEC)

Before his government service, Donald had a varied career as a professor, consultant, and entrepreneur. In the mid-1990s, he taught economics and finance at the University of Chicago Graduate School of Business. He then spent about a year-and-a-half managing large antitrust cases (e.g., Pepsi vs. Coke) at Charles River Associates in Washington, DC. After that, he took the plunge into the world of new ventures, serving as Chief Financial Officer of a health care software start-up in Austin, TX. After that fascinating experience, he started his career in public service.

Donald received his Ph.D. in Economics from the Massachusetts Institute of Technology and his B.A. in Mathematics a couple miles down the road at Harvard.

Visit: Donald Marron

4 Comments on Do Bitcoins Violate a Fundamental Economic Law?

  1. Is the price of bread the same in my country as it is in yours? Probably not, and seeing as how bitcoin is decentralized it would make sense if there were different markets and different prices. If only this was applied to things like oil. In canada, a particualar company (I forget its name) produces oil for less than $50 a barrel, yet they still sell it at the market price, therefore raking it in.

  2. It is actually simple, if you have BTC at mt gox and want to get out, what you do?
    Send bitcoins to another exchange, in doing this the supply at mt gox goes down and the supply in another exchange goes up, that in the short term should explain the price difference

  3. “For those customers, a Mt. Gox bitcoin is different from one anywhere else.”

    This is a roundabout way of thinking about this phenomenon.
    In reality MtGox Bitcoins are the same as elsewhere but their dollars are different!
    USD are less liquid at MtGox so they converge on a different price.

    So to answer your question: people buy dollars there when the arbitrage opportunity is judged to be greater than the perceived cost of diminished liquidity.
    Another reason is the network effect: MtGox still trades the greatest volume of them all. That makes other exchanges less interesting for trading large volumes because the slippage might surpass the arbitrage opportunity.

  4. You got everything right except the crucial bit.

    > “For those customers, a Mt. Gox bitcoin is different from one anywhere else.”

    In fact it’s precisely the opposite. It’s the MtGox USD which is different from everyone else’s. Bitcoins are fungible and freely transferable. It’s the legacy currency that’s crippled and broken, and therefore variable in value.

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