The World’s Cash Is Disappearing. Bankers Aren’t Sure Where It Went

Some Australians are burying it. The Swiss might be hiding it. The Germans are probably hoarding.

Banks are issuing more notes than ever and yet they seem to be disappearing off the face of the earth. Central banks don’t know where they have gone, or why, and are playing detective, trying to crack the same mystery.

The puzzle is especially perplexing since societies and companies are going cashless, given the boom in payments by cards and cellphone apps.

The value of U.S. dollars in circulation hit about $1.7 trillion last year ($12.4 billion of it in $1 bills; $1.3 trillion of it in $100 bills) according to the U.S. Federal Reserve. That is up from $1.2 trillion in 2013.

A Federal Reserve economist, Ruth Judson, wrote in a 2017 paper that about 60% of all U.S. currency, and about 75% of $100 bills, had left the country by the end of 2016-for a total of about $900 billion in U.S. dollars kept overseas. Socking those bills away provides some protection against economic turmoil, especially in countries with a record of instability in their own financial systems, the paper said.

In Australia, the stock of Australian bank notes on issue relative to the size of the economy is near the highest it has been in 50 years, said Philip Lowe, governor of Australia’s central bank. He showed off newly printed bank notes to diners at a recent event in Melbourne and estimated that about $2,000 in printed bills exists for every Australian.

“I, for one, don’t have anywhere near that amount” on hand, Mr. Lowe said.

Following the money trail can often mean encountering a motley cast of characters that wouldn’t look out of place in a detective novel. Dollar bills are often vital grease for criminal gangs and tax cheats. They are also popular with collectors who worry about a future collapse of the financial system.

Bankers aren’t just hunting down cash to satisfy their own curiosity. If central banks don’t know how much cash is out there, they could print too much currency and risk inflation.

Construction workers recently dug up an estimated $140,000 buried in packages at a site on Australia’s Gold Coast, prompting a police search to find the trove’s owner.

In September, a court in Germany ruled on a case brought by a man who stuffed more than 500,000 euros in a faulty boiler only to see it incinerated when a friend made a fix on a cold day while he was on vacation. The man sued his friend for the value of the lost bank notes plus interest. He lost.

“People hide their money everywhere,” said Sven Bertelmann, head of the Bundesbank’s National Analysis Centre in Mainz, Germany. Sometimes bank notes are buried in the garden, where they start decomposing, or hidden in attics, where they are used by mice for building nests.

“It happens again and again that people keep money in an envelope and then they shred it by mistake,” Mr. Bertelmann said. “We pick up the bank notes with tweezers and then start to put them together, like a jigsaw puzzle.”

The Bundesbank thinks more than 150 billion euros are being hoarded in Germany.

The Reserve Bank of Australia’s Note Issue Department decided to take an unusual approach: could fire-damaged bank notes help to determine how much money is being hoarded? Analysts even devised an equation based on the value of claims submitted by households for new bank notes to replace those that had been damaged by fires.

It didn’t work.

“Our estimates are only reliable if our assumptions are reasonable, which we believe is probably not the case,” lamented analysts at Australia’s central bank.

For one thing, they found wealthier people are less likely to suffer a fire because they live in cities near emergency services and have working fire alarms. That skewed results toward rural farmhouses built with wood.

The European Central Bank, and others, tried asking the public for help.

“Everyone says that they are not hoarding cash but the money is clearly somewhere,” said Henk Esselink, head of the issue and circulation section in the ECB’s currency management division.

Australia’s central bank says its best guess is that only around a quarter of the bank notes in circulation are used for everyday transactions. Up to 8% of cash is used in the shadow economy-tax avoidance or illegal payments-while as much as 10% could have been lost. That is $7.6 billion Australian dollars ($5.2 billion) missing at the beach or in couch cushions.

The biggest use of cash is as a store of wealth “in safes, under beds and at the back of cupboards, both here in Australia and elsewhere around the world,” Mr. Lowe, the RBA governor, said.

Officials at the Swiss National Bank ran with another theory: hoarded bank notes should wear out less because they aren’t being used for everyday transactions.

Demand for high-denomination bank notes tends to rise when interest rates are low, households feel distrustful of the banking system or people want to make transactions anonymously.

Generally, SNB officials found that hoarding of Swiss francs jumped around the year 2000, likely motivated by fear of the Y2K bug infecting computer systems, the bursting of the dot-com bubble, the September 11 terrorist attacks and introduction of the euro. The financial crisis that began in 2007 encouraged people to stash even more.

Around a third of New Zealand’s new bank notes headed overseas in 2017, up from 6% four years earlier. That happened around the time that tourism overtook dairy as the country’s main export money-spinner, leading officials to speculate on the role played by currency exchanges, especially in Asia.

The trail mostly ran cold after that. The bank could only identify the whereabouts of around 25% of New Zealand’s cash.

“Our sense is that we’re in the same boat as a lot of other central banks out there,” said Christian Hawkesby, assistant governor at the RBNZ. “We can’t fully explain why holdings of cash are rising and where they are going.”

By David Winning and James Glynn