Proposals for reform of the monetary system based either on public access to accounts with the central bank or on banking systems that are 100% backed by central bank reserves and government debt have proliferated since the financial crisis. A few have crossed my path in the past few days (e.g. here and here).
I have been making the point in a variety of posts on this blog that these proposals are based on the Monetarist misconception of the nature of money in the modern economy and likely to prove disastrous. While much of my time lately is being spent working up a formal “greek” presentation of these ideas, explaining them in layman’s terms is equally important. Thanks to comments from an attentive reader, here is a more transparent explanation. Let me start by quoting from an earlier post that draw a schematic outline of Goodhart’s “private money” model :
The simplest model of money is a game with three people, each of whom produces something another seeks to consume: person 2 produces for person 1, person 3 produces for person 2, person 1 produces for person 3. Trade takes place over the course of three sequential pairwise matches: (1,2), (2,3), (3,1). Thus, in each match there is never a double coincidence of wants, but always a single coincidence of wants. We abstract from price by assuming that our three market participants can coordinate on an equilibrium price vector (cf. the Walrasian auctioneer). Thus, all these agents need is liquidity.
Let the liquidity be supplied by bank credit lines that are sufficiently large and are both drawn down by our participants on an “as needed” basis, and repaid at the earliest possible moment. Assume that these credit lines – like credit card balances that are promptly repaid – bear no interest. Then we observe, first, that after three periods trade has taken place and every participant’s bank balance is zero; and, second, that if the game is repeated foerever, the aggregate money supply is zero at the end of every three periods.
In this model the money supply expands only to meet the needs the trade, and automatically contracts in every third round because the buyer holds bank liabilities sufficient to meet his demand.
Consider the alternative of using a fiat money “token” to solve the infinitely repeated version of the game. Observe that in order for the allocation to be efficient, if there is only one token to allocate, we must know ex ante who to give that token to. If we give it to person 3, no trade will take place in the first two rounds, and if we give it to person 2 no trade will take place in the first round. While this might seem a minor loss, consider the possibility that people who don’t consume in the first stage of their life may have their productivity impaired for the rest of time. This indicates that the use of fiat money may require particularized knowledge about the nature of the economy that is not necessary if we solve the problem using credit lines.
Why don’t we just allocate one token to everybody so that we can be sure that the right person isn’t cash constrained in early life? This creates another problem. Person 2 and person 3 will both have 2 units of cash whenever they are making their purchases, but in order to reach the equilibrium allocation we need them to choose to spend only one unit of this cash in each period. In short, this solution would require people to hold onto money for eternity without ever intending to spend it. That clearly doesn’t make sense.
This simple discussion explains that there is a fundamental problem with fiat money that ensures that an incentive compatible credit system is never worse and in many environments is strictly better than fiat money. This is one of the most robust results to come out of the formal study of economic environments with liquidity frictions (see e.g. Kocherlakota 1998).
In response to this I received the following question by email:
In your 3 person model, [why not allocate] a token to everybody? – I don’t understand how you reached the conclusion that “this solution would require people to hold onto money for eternity without ever intending to spend it”. If people have more units of cash than they need for consumption, the excess would be saved and potentially lent to others who need credit?
This question arises, because I failed in the excerpt from my post above to explain what the implications of “allocating a token to everybody” are when translated into a real world economy. In order for an efficient outcome to be achieved, you need to make sure that everybody has enough money at the start of the monetary system so that it is not possible that they will ever be cash-constrained at any point in time. In my simple model this just implies that everybody is given one token at the start of time. In the real world this means that every newborn child is endowed at birth with more than enough cash to pay the full cost of U.S. college tuition at an elite institution (for example).
Turning back to the context of the model, if the two people with excess currency save and lend it, we have the problem that the one person who consumes at the given date already has enough money to make her purchases. In short there is three times as much currency in the economy as is needed for purchases. What this implies is that we do not have an equilibrium because the market for debt can’t clear at the prices we have assumed in our model. In short, if we add lending to the model then the equilibrium price will have to rise — with the result that nobody is endowed with enough money to make the purchases they want to make. Whether or not an efficient allocation can be obtained by this means will depend on the details of how the lending process is modeled. (The alternative that I considered was that there was no system of lending, so they had to hold the token. Then when they had an opportunity to buy, choose to spend only one token, even though they were holding two tokens. This is the sense in which the token must be held “for eternity” without being spent.)
Tying this discussion back into the college tuition example. If, in fact, you tried to implement a policy where every child is endowed at birth with enough cash to pay elite U.S. college tuition, what we would expect to happen is that by the time these children were going to college the cost would have increased so that they no longer had enough to pay tuition. But then of course you have failed to implement the policy. In short, it is impossible to “allocate a token to everybody”, because as soon as you do, you affect prices in a way that ensures that the token’s value has fallen below the value that you intended to allocate. There’s no way to square this circle.
Connecting this up with bitcoin or deposit accounts at the central bank: the currently rich have a huge advantage in a transition to such a system, because they get to start out with more bitcoins or larger deposit accounts. By contrast in a credit-based monetary system everybody has the opportunity to borrow against their future income.
The problem with the credit-based monetary system that we have is that guaranteeing the fairness of the mechanisms by which credit is allocated is an extremely important aspect of the efficiency of the system. That is, in a credit-based monetary system fairness-based considerations are not in conflict with efficiency-based considerations, but instead essential in order to make efficiency an achievable goal.
Because of the failure to model our monetary system properly, we have failed to understand the importance of regulation that protects and supports the fair allocation of credit in the system and have failed to maintain the efficiency of the monetary system. In my view appropriate reforms will target the mechanisms by which credit is allocated, because there’s no question that in the current system it is allocated very unfairly.
The problem with proposals to eliminate the debt-based system is that as far as I can tell, doing so is likely to just make the unfairness worse by giving the currently rich a huge advantage that they would not have in a reformed and well-designed credit-based monetary system.