If a bank loans you money and you use it to build a house, or start a restaurant, then in due course there will be:
- new money, created by the loan; and
- a new, valuable asset — the house or restaurant — worth very roughly that amount of money.
Case by case these won’t always balance, but we trust private banks and borrowers to get it broadly right in aggregate. It all works out except for when it doesn’t.
But somebody had better be creating money in a growing economy. Otherwise the stock of desirable stuff will grow while the stock of money remains constant. And once that happens, people start hoarding money rather than doing the hard work of investing in new productive assets. But creating new productive assets is where the growth comes from, not to mention a big chunk of the jobs.
I doubt bank-created money is the only way to avoid deflation and depression. But it’s about the least centrally-controlled alternative I can think of.