How Central Banks Control the Money Supply With Interest Rates?

Central banks control how much money is in the economy by changing interest rates, like a playground leader deciding how many kids can join a game at once.

Imagine you have a piggy bank, and your friend has one too. If your friend says, “I’ll give you 10 candies if you lend me some coins,” that’s like an interest rate, the extra you get for sharing your money.

If the central bank wants more money in the economy, it lowers interest rates. That means borrowing money becomes cheaper, just like getting a discount on candy. More people and businesses want to borrow money because they can pay back less, so there’s more money moving around.

But if the central bank raises interest rates, it's like saying, “You’ll have to give me 15 candies for each coin you lend me!” That makes borrowing more expensive, so fewer people want to take out loans. As a result, less money is in motion, and the economy slows down a bit.

Think of the central bank as the playground leader who decides how many kids can join the game, by changing how fun or costly it is to play!