The dangers of printing money are well-documented. Too much money chasing too few goods leads to higher prices and lower growth. Hundreds of billions of pounds of so-called quantitative easing (QE) during the financial crisis skewed this perception as the Bank of England repeatedly fired up the printing presses to try to revive the UK’s ailing economy. Inflation at first failed to rear its ugly head, until it did. And policymakers and taxpayers are now counting the cost of Britain’s £895bn monetary experiment. QE is a process where Threadneedle Street creates money that is used to buy government bonds, known...