Supply and demand

Have you ever wanted the exact same toy as all your friends? Or maybe you’ve tried to sell lemonade on a super hot day and suddenly everyone on the block wants a cup. You feel a special kind of excitement, a busy, buzzy feeling. But what about selling lemonade on a chilly, rainy day? Not so many customers, right? I’m the secret reason for that difference. I am the invisible push and pull you feel when you buy, sell, or trade things. I am in every store, every market, and even in your school cafeteria when everyone wants the pizza slices and no one wants the lima beans. I help decide how much of something there is and how much people want it. Hello there. You can call me Supply and Demand, and I have a story to tell you.

I am made of two parts that work together like a see-saw. My first part is named Supply. Supply is just a word for how much of something there is. Think of a farmer who has a huge field of juicy red strawberries in the summer. That’s a very big supply. My other part is named Demand. Demand is how much everyone wants that thing. If it’s a hot summer day and everyone wants to make strawberry milkshakes, that’s a very high demand. When lots of people want something but there isn’t much of it, the price goes up, just like one side of a see-saw. But when there’s a ton of something and not many people want it, the price goes down. People have known about me for thousands of years, whenever they traded shells or food. But a very thoughtful man from Scotland named Adam Smith wrote all about me in a famous book called 'The Wealth of Nations' on March 9th, 1776. He helped everyone understand my see-saw game.

You see me working every single day. I help store owners decide how many gallons of milk to order. I help video game makers figure out how many copies of a new game to create. I am why flowers cost more on Valentine's Day because of super high demand and why winter coats are on sale in the spring because of super low demand. Understanding me is like having a secret superpower. It helps people know the best time to buy things and helps them run businesses so they don’t run out of what you need. I’m not just about money. I’m about making sure that the things people want and need can get to them. From the farmer growing your food to the person baking your birthday cake, I am there, quietly helping the world share its amazing stuff. And the more you notice me, the smarter you'll be about how the world works.