Okay kiddo, let me explain the cost-push theory to you. Imagine you are running a lemonade stand. You need lemons, sugar, and water to make the lemonade. But one day, the cost of lemons goes up because there's a frost that damages the lemon trees. This means that you have to pay more for your lemons.
Now, in order to still make a profit, you have two choices: either raise the price of your lemonade or cut costs somewhere else. If you raise the price of your lemonade, then your customers may not want to buy it anymore because it's too expensive. But if you cut costs somewhere else, then maybe you don't use as much sugar or water in your recipe. But if you do that, your lemonade might not taste as good and you might lose customers that way.
The cost-push theory is a theory that says when the cost of something goes up, like the cost of lemons, it can cause prices to go up too. This is because the people who make and sell things, like lemonade, have to pay more for their supplies and so they need to charge more for their products in order to keep making a profit.
So, if a lot of things that are needed to make products, like the lemons in our example, go up in price, then it can cause inflation, which means that money doesn't go as far anymore. That's like if you used to be able to buy five things with $10, but now you can only buy three things because everything costs more.
Does that help you understand the cost-push theory, kiddo?