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# Supply and demand curves in foreign exchange

In this video, learn about how the model of the foreign exchange market is used to represent the determination of exchange rates.

## Want to join the conversation?

• Because USD:RMB mathematically has to be the reciprocal of the RMB:USD rate, is the eventual exchange rate between these two currencies affected by the demand and supply of both currencies? If so, how would you show that?

e.g. How would you show an increase in demand for the Yuan from the US translating into a weakening of the dollar on the respective diagram for the US Dollar market?
(3 votes)
• In the video Sal talks about the Foreign exchange for Yuan, and how the demand shifts to the right. Would the Foreign exchange for US Dollar relative to the Yuan have its demand or supply shift to the left? Since more people want to exchange their Dollars for Yuan? Or would it not have any impact on the exchange for US Dollar?
(2 votes)
• how to convert 100 yuan to dollar
200 dollar to yuan
(2 votes)
• 10 yuan is one dollar, so for the first question, 10*10 yuan = 10 dollars, and for the second, 200 * 10 yuan = 200 dollars = 2000 yuan.

Hopefully this helps, and I hope I didn’t get you confused.
(1 vote)
• Why is it US dollars in terms of Chines Yuan on the Y axis and not the other way round?
(1 vote)
• In the video, Sal is measuring the price of a yuan in terms of dollars. If you notice on the Y axis it says US dollars per Chinese yuan. The mathematical expression for that would be 1 yuan = 10 cents, or 1 yuan = 15 cents. So the exchange rate is based on the yuan. You could do it the other way around and measure the price of the dollar in terms of the yuan and the expression for that would be 1 dollar = 10 yuan.
(1 vote)

## Video transcript

- [Instructor] In a previous video, we've given an intuition on what foreign exchange markets are all about. In particular, we talked about the foreign exchange market between the U.S. dollar and the Chinese yuan. What we're going to do in this video is think about the same idea, but think about it in terms of graphs and the types of economic models that we're used to seeing in an introductory macroeconomics course. So what we're going to focus on in this video is the foreign exchange market. Foreign exchange market for the Chinese yuan. Now, we're going to think about it in terms of supply and demand curves. It can be a little bit confusing because we're gonna be thinking of the price of the yuan in terms of another currency, in this case the dollar, although you could do it in terms of other currencies, the pound or the euro or whatever else. Now, this can be a little bit confusing because we're going to be thinking about currency on both axes. But let's first think about the horizontal axis that when we're thinking about most markets, that is our quantity axis. And here once we're going to think about quantity. We're gonna think about the quantity. Quantity of Chinese yuan. And then our vertical axis, we're essentially going to be thinking about the price of the Chinese yuan. But how do you think about the price of a currency? Well, we're going to think of it in terms of another currency. And for the sake of this video, that other currency is going to be the U.S. dollar. So this is going to be U.S. dollars per Chinese yuan. And I encourage you, pause this video. Think deeply about why it's U.S. dollars per Chinese yuan, as opposed to Chinese yuan per U.S. dollars. And think about why I put the quantity of Chinese yuan here instead of the quantity of U.S. dollars, because this is the foreign exchange market for the Chinese yuan. I could have done another chart where it's the foreign exchange market for the U.S. dollar, in which case then my quantity would be U.S. dollar. And then I would think of how much of some other currency per U.S. dollar. So I would say maybe how much Chinese yuan per U.S. dollar? But here it's the other way around. I'm in the market for the Chinese yuan. So let's think about the supply and demand curves and which way they would work. Well, imagine that people are offering very few U.S. dollars per Chinese yuan. Well, in that world, a lot of people might not wanna convert their yuan into dollars. They might not offer them up for supply to be converted into U.S. dollars. The quantity of Chinese yuan, if the price for the Chinese yuan is low, might be pretty low. And as the price people are willing to pay in terms of dollars goes up, well, more and more people might be willing to transact. So our supply curve, and here we're talking about the supply for Chinese yuan, is likely to increase as people are willing to pay more for those yuans. And this is like many markets that we've seen before. It's just a little bit less intuitive because we're thinking about markets for one currency in terms of another currency. Now, what about the demand curve? Well, the demand curve is gonna look like a lot of demand curves we've seen. If the price of a Chinese yuan is high, well, very few people are going to demand it. And as the price of the Chinese yuan in terms of dollars is lower and lower, more and more people might demand more Chinese yuan, go like, "Hey, it's cheaper now in terms of U.S. dollars." So this is what a demand curve might look like. And as you can imagine, this point is our equilibrium point, and it would tell us our equilibrium exchange rate. We could call that our equilibrium exchange rate, and this would be our equilibrium quantity. So, for example, let's say that our equilibrium quantity, and let's say this is the quantity that changes hands in some time period, so let's say per day. Let's say or equilibrium quantity is equal to 1,000 yuan. 1,000 yuan. And let me just call this Q sub one, is 1,000 yuan. These numbers are very low. Real exchange markets, we might be talking about billions or tens or hundreds of billions or even sometimes trillions of various currency. But let's just say for argument it's 1,000 yuan is our current equilibrium exchange quantity per day. And let's say this exchange rate, e sub one, is equal to 10 cents per yuan. So 10 cents, or 1/10 of a U.S. dollar per Chinese yuan. So that's our current exchange rate. Now, let's say for some reason, all of a sudden Americans become increasingly interested in converting their currency. Maybe they want to invest in China. Maybe all of a sudden the Chinese say, "Hey, Americans, come buy property in China." A lot of people are interested. Well, what would happen here? Well, then the demand for yuan would increase because you could only buy that property in China with yuan, not with U.S. dollars. What would happen here? Well, your demand curve would shift to the right like we've seen before. If we call this D one, then we could get to a new demand curve that might look something like this, D two. Now, what would happen if our equilibrium exchange rate doesn't change? Well, if this is our exchange rate, if this were to stay our exchange rate, now all of a sudden a higher quantity is being demanded than is being supplied. The Americans in this situation, or it actually doesn't even have to be Americans. It could just be whoever's holding U.S. dollars, there's demand for more than 1,000 yuan per day. Maybe this is 1,500 yuan or whatever it might be. What you would naturally see is that price of the yuan in terms of U.S. dollars will go up until you get to an equilibrium point. And on the first video when we talk about the intuition of foreign exchange markets, we talk about why this would be. So you would then get to a new equilibrium, right over here, this is e sub two, and a new equilibrium quantity. Let's call this Q two. Our new equilibrium quantity, Q two, might be 1,200 yuan per day versus 1,000 yuan per day. And our new equilibrium exchange rate, maybe this is now equal to 15 cents per yuan instead of 10 cents per yuan. So big picture, you can think of the foreign exchange market in a lot of ways like we've looked at other markets in macroeconomics. It takes a little bit of an intuitive leap to just think about the market for one currency in terms of another.