There are two problems with using Bitcoin as a substitute for
conventional currencies. One is that transaction costs are high; I gather
there are some proposals to solve that. The other is that its value is
very unstable. So far that has been a plus, since the value has mostly gone up.
But in general it is a minus, since it means that if you are holding a
substantial amount of currency for transactions you are also speculating
in its value, whether or not you want to.
That raises the interesting question of whether it is possible to construct a cryptocurrency with a stable value.
Basecoin
is a recent attempt to do so. I have not examined how it works carefully
enough to offer any opinion on it, but I think in principle the project is
doable.
Suppose you want a currency which exchanges at one for one with
the U.S. dollar. There is a real world example of a solution to that problem, although it
was for paper currency not cryptocurrency–the Hong Kong dollar issued by
the Bank of Hong Kong and Kowloon (I think also by a second bank–all this is from memory, so details may be off). It
maintained a constant exchange rate with the dollar (not one for one) by
a simple mechanism. Any time the $HK went above the target rate the
bank printed more, any time it went below they bought some and took them
off the market.
Basecoin works on the same principle. In theory it
eventually shifts from pegged to the dollar to pegged to a market basket
of goods.
Pre-bitcoin, Chaumian digital cash was supposed to provide a currency
that could be exchanged by sending messages, with neither party having
to trust or know the identify of the other. The problem was that it
required an issuer, a trusted bank. A digital currency makes enforcing
money laundering rules hard, an anonymous digital currency, which the
Chaumian version would have been, makes it impossible, so governments
very much don’t want it to exist, which makes it hard to establish a
trusted issuer.
The beauty of Bitcoin is that there is no issuer, so the
problem goes away.
How do you maintain a stable digital currency without an issuer, a
private central bank? I do not know the details of how Basecoin proposes
to do it, but here is my version:
You start with ten issuers, each a respected private firm,
probably in different countries, each with a private key/public key pair
that it can use to prove its identity. You have some way that the
software can measure the exchange rate between your currency and the
dollar–the Ethereum people I have talked with refer to a mechanism for reporting
real world facts to the software as an oracle and have some ingenious
ideas for making one work. The software then establishes the following
rules:
1. Any time the exchange rate is above the target, one of the issuers
can create one more coin. Which issuer gets to do it depends on which ones
created the last nine coins–they go in sequence.
2. Any time the exchange rate is below the target, one of the
issuers, again in sequence, is supposed to buy a coin and take it out of
circulation.
3. An issuer that fails to obey rule 2 is no longer in the sequence
for rule 1. Each time it fails to obey it, its debt to the system goes
up by one. Only when it has repaid that debt by taking the corresponding
number of coins out of circulation does it rejoin the sequence of
issuers.
4. If the exchange rate is above the target and the issuer whose turn
it is to issue a dollar doesn’t, after an hour it loses its turn to the
next issuer in sequence.
Assume an expanding demand for the currency, first from its initial spread, in the long term from
economic growth. Issuers profit because they
are getting an interest free loan in the form of the
the coins they print to hold the value down to a dollar. That
gives each issuer an incentive to obey rule 2, so as to maintain its
ability to issue.
Rule 4 exists mostly to cover the possibility of an issuer going out
of business or being shut down by its government. There should be a
mechanism making it possible, if that happens, to transfer its status to
a new issuer. In the simplest case, that is done by selling the private
key that proves its identity to another firm that wants to replace it.
What is wrong with this proposal?
I was pointed at this problem, and at Basecoin, by
my son Patri. I gather it has been discussed at some length recently, so
I may well be reinventing the wheel, but I find it more interesting to
think such things out for myself than to start by reading what other
people have written.
That reminds me of an anecdote about my friend and ex-colleague the
late Gordon Tullock. Someone prominent wrote an article. Tullock wrote a
rebuttal. The original author wrote a response, claiming that Tullock
had entirely misunderstood the original article. It included the line
(by memory so not verbatim):
We have all been long impressed by how much Professor
Tullock has written. It is even more impressive to realize that he has written so
much without being able to read.