The Mundell-Fleming model is like a big puzzle that helps us understand how changes in one country can affect other countries around the world.
Imagine you have a toy car that you really love, and you want to buy another toy car from a different store. But the store where the second car is sold is in a different country. So you need to exchange some of your money to buy the toy car from that country.
Now let's say that your country decides to make some changes to its monetary or fiscal policies, like lowering interest rates or increasing government spending. These policies can affect the exchange rate of your country's currency, which means that you might not be able to buy the same amount of toy cars from the other country as before.
The Mundell-Fleming model helps us understand how these policies and changes can affect the balance of trade between countries, and how this can impact their economies. It takes into account different factors like the exchange rate, international capital flows, and how much the governments of each country are spending or saving.
By using this model, economists can predict how changes in one country's policies or economic conditions might affect other countries around the world, and help them make decisions to minimize potential negative impacts.