There is more to international exchange than the flow of goods and services across borders: financial assets are also exchanged. When there are differences in real interest rates between two countries that allow for the flow of financial capital, that capital flows to the country with the relatively higher real interest rate and out of the country with the relatively lower real interest rate.
This has a few important implications. First, differences in real interest rates affect the balance of payments, exchange rates, and the market for loanable funds. Second, since central banks can influence the domestic interest rate (at least in the short run), they can also affect capital flows. Finally, and perhaps most importantly, this means that one country’s business cycle can affect another country, which is why we sometimes see recessions and financial crises spread between countries.

Key Terms

Key Term Definition
capital controls legal restrictions on the movement of capital between countries
financial contagion the spread of economic conditions, especially negative market disturbances, from one country to another; For example, a recession in Hamsterville has a negative effect on the economy of Johnsrudia.

Key takeaways

Financial capital flows to the highest real interest rate

An open economy lacks capital controls, and when there are no controls on the movement of financial assets, people will be attracted to assets with higher real interest rates.
Imagine you are a resident of Hamsterville, lying on the beach while reading an international financial newspaper. You see that interest rates in Johnsrudia have increased from 2% to 6% because high investment demand has increased the demand for loanable funds. You remember your broker was going to buy $10,000 worth of Hamsterville bonds being issued today, on which you expected only a 3% return. You frantically call her and tell her to buy assets in Johnsrudia instead.
What effect does this have? A lot! First, you just reduced the supply of loanable funds in Hamsterville, which increases real interest rates in Hamsterville. Second, Johnsrudia is going to require you to buy assets there using their currency, the Johnsrudian Walter. The supply of dollars increases, which depreciates the dollar, and the demand for the Johnsrudian Walter increases, which appreciates the Walter.

Central banks can influence the movement of capital, exchange rates, and net exports

Central banks can influence the movement of capital because they can influence interest rates in the short run. Suppose instead you read that the central bank of Hamsterville has bought bonds, lowering the domestic nominal interest rate. Well, the effect would be the same! Now your rate of return domestically is less than it is internationally, so you send your savings elsewhere.

Expansionary monetary policy and expansionary fiscal policy can potentially impact the exchange rate in different ways

Recall that expansionary monetary policy and expansionary fiscal policy both had the same goal: increase aggregate demand and output and decrease the unemployment rate. However, each of these has the opposite impact on interest rates in the short run, which means they also have opposite effects on exchange rates.
 

Common Misperceptions:

Capital vs. Financial Capital

Capital and financial capital are not the same! Anytime you talk about the movement of “capital”, you should be careful to specify which you are talking about. The movement of capital between countries would be something like computer equipment or tractors being purchased from another country. The movement of financial capital is sending savings to another country