Andy Haldane and BOEcoin

The 1995 British two pound "Dove" coin

The Bank of England's chief economist Andrew Haldane recently called for central banks to think more imaginatively about how to deal with the technological constraint imposed by the zero lower bound on interest rates. Haldane says that the lower bound isn't a passing problem. Rather, there is a growing probability that when policy makers need three percentage points of headroom to cushion the effects of a typical recession, that headroom just won't be there.

Haldane pans higher inflation targets and further quantitative easing as ways to slacken the bound, preferring to focus on negative interest rates on paper currency, a topic which gets discussed often on this blog. He mentions the classic Silvio Gesell stamp tax (which I discussed here), an all out ban on cash as advocated by Ken Rogoff, and Miles Kimball's crawling peg (see here).

According to Haldane, the problem with Gesell's tax, Rogoff's ban (pdf), and Kimball's peg is that each of these faces a significant 'behavioural constraint.'  The use of paper money is a social convention, both as a unit of account and medium of exchange, and conventions can only be shifted at large cost. Tony Yates joins in, pointing out the difficulties of the Gesell option. Instead, Haldane floats the possibility of replacing paper money with a government-backed cryptocurrency, or what we on the blogosphere have been calling Fedcoin (in this case BOEcoin). Unlike cash, it would be easy to impose a negative interest rate on users of Fedcoin or BOEcoin, thus relaxing the lower bound constraint. Conventions stay intact; people still get to use government-backed currency as a medium of exchange and unit of account.*

While I like the way Haldane delineates the problem and his general approach to solving it, I'm not a fan of his chosen solution. As Robert Sams once pointed out, Fedcoin/BoEcoin could be so good that it ends up outcompeting private bank deposits, thus bringing our traditional banking model to an abrupt end. Frequent commenter JKH calls it Chicago Plan #37, a reference to a depression-era reform (since resuscitated) that would have outlawed fractional reserve banking. If Haldane is uncomfortable with the Gesell/Rogoff/Kimball options for slackening the lower bound because they interfere with convention, he should be plenty worried about BOEcoin.

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I do agree, however, with Haldane's point that the apparatus adopted to loosen the constraint should interfere with convention as little as possible. We want the cheapest policies; those that only slightly impede the daily lives of the typical Brit on the street while securing the Bank of England a sufficient amount of slack.

With that in mind, here's what I think is the cheapest way for the Bank of England to slacken the lower bound: just freeze the quantity of £50 bills in circulation. Yep, it's that easy. There are currently 236 million £50 notes in circulation. Don't print any more of them, Victoria Cleland.**

I call this a policy of embargoing the largest value note. How does it work?***

Say that in the next crisis, the Bank of England decides to chop rates from 0.5% to -2.0%. Faced with deeply negative interest rates, the UK runs smack dab into the lower bound as Brits collectively try to flee into banknotes. After all, banknotes offer a safe 0% return, the £50 note being the chosen escape route since those are the cheapest to store and convey.

Flooded with withdrawal requests, banks will quickly run out of £50s. At that point the banks would normally turn to the Bank of England to replenish their stash in order to fill customers' demands. But with the Bank of England having frozen the number of £50s at 236 million and not printing any new ones, bankers will only be able to offer their customers low denomination notes. But this will immediately slow the run for cash since £20s, £10s, and £5s are much more expensive to store, ship and transfer than £50s. Whereas people will surely prefer a sleek high denomination note to a deposit that pays -2%, they will be relatively indifferent when the choice is between a bulky low denomination cash and a deposit that pays -2%. Thus the lower bound has been successfully softened by an embargo on the largest value note.

Once negative interest rates have served their purpose and the crisis has abated, they can be boosted back above 0% and the central bank can unfreeze the quantity of £50s. Everything returns to normal.

A few conventions will change when the largest value note is embargoed.

1. People will no longer be able to convert £50 worth of deposits into a £50 note. Instead they'll have to be satisfied with getting two £20s and a £10. That doesn't seem like an expensive convention to discard. And if folks really want to get their hands on £50s, they'll still be able to buy them in the secondary market, albeit at a small premium.

2. In normal times, £50 notes always trade at par. Because their quantity will be fixed under this scheme, £50s will rise to a varying premium above face value whenever interest rates fall significantly below zero. For instance, at a -2.0% interest rate a £50 note might trade in the market at £51 or £52.

The par value of £50 notes is a cheap convention to overturn. The majority of the British population probably don't deal in £50s anyways. Those who do use £50 notes in their daily life will have to get used to monitoring their market price so that they can transact at correct prices. But the inconveniences faced by  this tiny minority is a small cost for society to pay in order to slacken the lower bound.

3. Importantly, there will be no need to proclaim a unit of account switch upon the enacting of an embargo on £50s; the switch will be seamless.

Because the £50 was never an important part of day-to-day commercial and retail existence, come negative interest rates no retailers will set their prices in terms of a £50 standard. If they do choose to set sticker prices in terms of the £50 note, they will find that if they want to preserve their margins they will have to levy a small surcharge each time someone pays with £20s, £10s, and £5s and bank deposits. Given the prevalence of these payment options, that means surcharging on almost every single transaction. That's terribly inconvenient. Far better for a retailer to set sticker prices in terms of the dominant payments media—£20s, £10s, and £5s and bank deposits—and provide a small discount to the rare customer that wants to pay with £50s.

It's entirely possible that the majority of retailers will not bother offering any discount whatsoever on £50s. This would effectively undervalue the £50 note. Gresham's Law tells us that given this undervaluation, the £50 will disappear from circulation as it gets hoarded under people's mattresses. For the regular British citizen, never seeing £50s in circulation probably won't change much. And anyone who does want a £50 can simply advertise on Craig's list for one, offering a high enough premium to draw it out of someone's hoard.

In closing, a few caveats. The figures I am using in this post are ballpark. It could be that a policy of freezing the supply of £50 notes allows the Bank of England to get to -2%. But maybe it only allows for a level of -1.75%, or maybe it slackens the bound so much as to allow a -2.5% rate.

Haldane mentions that the Bank of England could need 3% of headroom to combat subsequent recessions. But as Tony Yates has pointed out, in 2008 bank officials calculated that a -8% rate was needed. The Bank could get part way there by not only embargoing the £50 but also the next highest value note; the £20. But that probably wouldn't be enough. As ever smaller notes have their quantities frozen, this starts to intrude on the lives of the people on the street, making the policy more costly. If it needs to slacken the lower bound in order to allow for rates of -8%, I think the Bank of England should be planning for a heftier policy like Miles Kimball's crawling peg. After all, when the sort of crisis that requires such deeply negative rates hits, the last thing we should be worried about is disturbing a few conventions. Until another 2008-style crisis hits, embargoing large value notes might be the least intrusive, lowest cost option. 

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*Of these policies, I think Miles Kimball's plan is by far the best one.
**Specifically, the Bank would only print new bills to replace ripped/worn out bills. Otherwise the outstanding issue will wear out and become easier to counterfeit. As for Scotland, which issues 100 pound notes, their quantity would have to be fixed as well.
*** I first mentioned the idea of embargoing large notes in relation to the Swiss 1000 CHF note, and later elaborated on it in the Lazy Central Banker's Guide to Escaping Liquidity Traps.