Imagine that you live in a world without any banks. Further imagine that you have saved a substantial sum of money that you don’t plan on spending anytime soon. What can you do with those funds?
One answer is that you could simply store the money—say, put it under your bed or in a safe. The money would always be there if you need it, but it would just sit there, not earning any interest.
Alternatively, you could lend the money out, say, to a growing business. This would have the great advantage of putting your money to work, both for you, since the loan would pay interest, and for the economy, since your funds would help pay for investment spending. There would, however, be a potential disadvantage: if you needed the money before the loan was paid off, you might not be able to recover it.
It’s true that we asked you to assume that you had no plans for spending the money soon. But it’s often impossible to predict when you will want or need to make cash outlays; for example, your car could break down or you could be offered an exciting opportunity to study abroad. Now, a loan is an asset, and there are ways to convert assets into cash. For example, you can try to sell the loan to someone else. But this can be difficult, especially if you need cash on short notice. So, in a world without banks, it’s better to have some cash on hand when an unexpected financial need arises.
In other words, without banks, savers face a trade-off when deciding how much of their funds to lend out and how much to keep on hand in cash: a trade-off between liquidity, the ability to turn one’s assets into cash on short notice, and the rate of return, in the form of interest or other payments received on one’s assets. Without banks, people would make this trade-off by keeping a large fraction of their wealth idle, sitting in safes rather than helping pay for productive investment spending. Banking, however, changes that by allowing people ready access to their funds even while those funds are being used to make loans for productive purposes.