Besides taking deposits, banks also served another purpose: lending.
Before the Great Depression arrived in 1929, many American families bought cars, electrical appliances, furniture, and so on through installment plans. Electrification not only increased productivity but also changed people's lives. Radios, washing machines, sewing machines, vacuum cleaners, and refrigerators—the luxury item invented in 1919—entered countless homes.
Yet Americans did not have the cash to buy these products, so consumer credit became a defining feature of the 1920s.
Installment payments had originally been disliked by other social classes; even in 1914, people did not know how to use them.
In short, banks lent money to businesses to expand production capacity and to families to expand their purchasing power. So where did American banks get their money?
Many historians studied the revelry before the Great Depression. After 1929, people stopped putting their money in banks. Americans used to spend whatever money they had, but during the Great Depression, they developed the habit of saving it, hiding it in socks or wine cellars.
Once currency hoarding appeared, it became an important factor in a vicious cycle. After Franklin D. Roosevelt came to power, he used radio to hold "Fireside Chats" with people across America, persuading them to deposit their money in more reputable banks.
Gringotts had no credit business. It only fulfilled a custodial role. Goblins were also responsible for minting currency, remaking worn Galleons and silver Sickles, and exchanging money with Muggle currencies. But compared with green paper notes, goblins preferred gold and silver.
If Percival truly had been one of the founders involved in establishing Gringotts, then he might indeed have known why. At the time, he was a professor of Divination at Hogwarts and one of the leaders of the small group San Bakar belonged to. The goblins had shown