When you lend When you lend somebody money, they usually have to pay you for the privilege.
That has been a bedrock assumption across centuries of financial history. But it is an assumption that is increasingly being tossed aside by some of the world’s central banks and bond markets.
A decade ago, negative interest rates were a theoretical curiosity that economists would discuss almost as a parlor game. Two years ago, it began showing up as an unconventional step that a few small countries considered. Now, it is the stated policy of some of the most powerful global central banks, including the European Central Bank and the Bank of Japan.