Supply and Demand

Supply and Demand, written by Keith and Sarah Kordermarten. Focus Question. What are supply and demand, and how are they related?

《供求关系》，作者：基思·科德马滕、萨拉·科德马滕。 核心问题。 什么是供给和需求，二者有什么关联呢？

Who sets the price? Have you ever wanted to buy something but didn't end up getting it? Was it too expensive? Maybe it was a new product, such as a t -shirt with your favorite movie character on it. You might have gone back to the store once the t -shirt was on sale. Did you buy it then? Probably not. You'd rather get a shirt for a newer movie. Why do things cost what they do? When people decide to buy something, they take part in an interaction with the seller. Any place where sellers and buyers come together to do business is called a market. In a market, buyers exchange money with sellers for goods such as toys and services such as haircuts. You have probably noticed that goods and services can vary widely in price. Even the same kinds of things such as cars, clothes, or food can be cheap or expensive.

价格是谁定的呢？ 你有没有过想买一样东西，最后却没买到的经历？ 是不是因为它太贵了呢？ 它可能是一件新商品，比如印着你最爱的电影角色的T恤。 说不定这件T恤打折后，你又再去了一趟商店。 那时候你买下它了吗？ 多半没有。 你更想买印着新电影的T恤呀。 为什么商品会是现在这个价格呢？ 当人们决定买东西时，就会和卖家产生互动。 任何买卖双方碰面做生意的地方，都叫做市场。 在市场里，买家付钱给卖家，换玩具这类商品，还有剪头发这类服务。 你肯定也发现了，商品和服务的价格差异很大。 哪怕是同一种商品，比如汽车、衣服或是食物，也会有便宜有贵。

People called economists attempt to explain how prices work through economics, the study of buying, selling, and wealth. They use the law of supply and demand to describe how and why the cost of goods and services in the market changes. Supply refers to how much there is of a good or service. Demand indicates how much of that good or service people want.

经济学家尝试通过经济学解释价格的运作规律，经济学是研究买卖与财富的学问。 他们用供求定律来描述，市场中商品和服务的价格为什么会变化、又是怎么变化的。 供给指的是某种商品或服务一共有多少。 需求指的是人们想要多少这种商品或服务。

Bear in mind that prices change regularly because supply and demand are constantly changing. This also works in reverse. Changes in price can, in turn, cause changes in both supply and demand. Did the movie with the T -shirt you wanted fail? Was it a great success? The movie's popularity affects the price of the merchandise connected to it. Supply, demand, and price are always changing and influencing one another from moment to moment. It turns out that buyers like you have an effect on how much goods and services cost.

要知道，价格会经常变动，因为供给和需求一直在变化。 反过来，规律也同样成立。 而价格的变化，反过来也会同时改变供给和需求。 你想买的那件T恤印的电影是不是不受欢迎呀？ 还是说，它大获成功了呢？ 电影的人气会影响它周边商品的价格哦。 供给、需求和价格一直在变化，还时时刻刻互相影响。 原来呀，像你这样的买家，也会影响商品和服务的价格哦。

Supply and demand at work. Picture this. Your stomach is grumbling. A local restaurant has a lunch special on chicken sandwiches. Two for the price of one. What a deal. In this case, the price of the sandwich decreased, and the price drop created a spike in demand. Think about the sandwiches in this example from the seller's point of view. Why did the restaurant offer the two for one deal? Perhaps it had a few too many chicken patties. It might have needed to sell them by a certain date to avoid spoilage. In this case, the restaurant had more chicken patties than people wanted to buy. This situation is called a surplus. When there is a surplus in the market, prices often go down.

供求规律在生活中的应用。 想象一下这个场景。 你的肚子咕咕叫了。 家附近的餐厅推出了鸡肉三明治的午餐特价。 买一送一哦。 太划算了吧。 在这个例子里，三明治降价了，降价让需求一下子暴涨。 现在我们从卖家的角度，再看看这个三明治的例子。 餐厅为什么要推出买一送一的活动呢？ 可能是因为他们进了太多鸡肉饼啦。 他们得在保质期前卖掉，不然肉就坏了。 这种情况就是，餐厅的鸡肉饼比人们想买的多很多。 这种情况就叫做过剩。 当市场出现过剩时，价格通常就会下降。

In general, sellers are motivated to sell goods and services for as much money as the market will allow. Sellers try to make a profit by selling goods and services for more money than they cost to make. Buyers, on the other hand, are often motivated to purchase goods and services for as little money as possible. The tension between the two helps balance supply and demand. Let's consider how this works. If a seller prices an item too high, demand will often

一般来说，卖家都希望能在市场允许范围内，卖个尽可能高的价钱。 卖家都想赚利润，卖价要比生产成本更高才行。 反过来，买家都希望能花尽可能少的钱买到商品和服务。 双方之间的这种拉扯刚好能平衡供求关系。 我们来看看这是怎么运作的吧。 如果卖家把一件商品的价格定得太高，需求往往会