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system, which in turn reduces the money supply. Conversely, a lower discount rate encourages bank borrowing from the Fed, increases the quantity of reserves, and increases the money supply.

The Fed uses discount lending not only to control the money supply but also to help financial institutions when they are in trouble. For example, in 1984, rumors circulated that Continental Illinois National Bank had made a large number of bad loans, and these rumors induced many depositors to withdraw their deposits. As part of an effort to save the bank, the Fed acted as a lender of last resort and loaned Continental Illinois more than $5 billion. Similarly, when the stock market crashed on October 19, 1987, many Wall Street brokerage firms found themselves temporarily in need of funds to finance the high volume of stock trading. The next morning, before the stock market opened, Fed Chairman Alan Greenspan announced the Fed’s “readiness to serve as a source of liquidity to support the economic and financial system.” Many economists believe that Greenspan’s reaction to the stock crash was an important reason why it had so few repercussions.

PROBLEMS IN CONTROLLING THE MONEY SUPPLY

The Fed’s three tools—open-market operations, reserve requirements, and the discount rate—have powerful effects on the money supply. Yet the Fed’s control of the money supply is not precise. The Fed must wrestle with two problems, each of which arises because much of the money supply is created by our system of fractional-reserve banking.

The first problem is that the Fed does not control the amount of money that households choose to hold as deposits in banks. The more money households deposit, the more reserves banks have, and the more money the banking system can create. And the less money households deposit, the less reserves banks have, and the less money the banking system can create. To see why this is a problem, suppose that one day people begin to lose confidence in the banking system and, therefore, decide to withdraw deposits and hold more currency. When this happens, the banking system loses reserves and creates less money. The money supply falls, even without any Fed action.

The second problem of monetary control is that the Fed does not control the amount that bankers choose to lend. When money is deposited in a bank, it creates more money only when the bank loans it out. Because banks can choose to hold excess reserves instead, the Fed cannot be sure how much money the banking system will create. For instance, suppose that one day bankers become more cautious about economic conditions and decide to make fewer loans and hold greater reserves. In this case, the banking system creates less money than it otherwise would. Because of the bankers’ decision, the money supply falls.

Hence, in a system of fractional-reserve banking, the amount of money in the economy depends in part on the behavior of depositors and bankers. Because the Fed cannot control or perfectly predict this behavior, it cannot perfectly control the money supply. Yet, if the Fed is vigilant, these problems need not be large. The Fed collects data on deposits and reserves from banks every week, so it is quickly aware of any changes in depositor or banker behavior. It can, therefore, respond to these changes and keep the money supply close to whatever level it chooses.

CASE STUDY BANK RUNS AND THE MONEY SUPPLY

Although you have probably never witnessed a bank run in real life, you may have seen one depicted in movies such as Mary Poppins or It’s a Wonderful Life. A bank run occurs when depositors suspect that a bank may go bankrupt and, therefore, “run” to the bank to withdraw their deposits.

Bank runs are a problem for banks under fractional-reserve banking. Because a bank holds only a fraction of its deposits in reserve, it cannot satisfy withdrawal requests from all depositors. Even if the bank is in fact solvent (meaning that its assets exceed its liabilities), it will not have enough cash on hand to allow all depositors immediate access to all of their money. When a run occurs, the bank is forced to close its doors until some bank loans are repaid or until some lender of last resort (such as the Fed) provides it with the currency it needs to satisfy depositors.

Bank runs complicate the control of the money supply. An important example of this problem occurred during the Great Depression in the early 1930s. After a wave of bank runs and bank closings, households and bankers became more cautious. Households withdrew their deposits from banks, preferring to hold their money in the form of currency. This decision reversed the process of money creation, as bankers responded to falling reserves by reducing bank loans. At the same time, bankers increased their reserve ratios so that they would have enough cash on hand to meet their depositors’ demands in any future bank runs. The higher reserve ratio reduced the money multiplier, which also reduced the money supply. From 1929 to 1933, the money supply fell by 28 percent, even without the Federal Reserve taking any deliberate contractionary action. Many economists point to this massive fall in the money supply to explain the high unemployment and falling prices that prevailed during this period. (In future chapters we examine the mechanisms by which changes in the money supply affect unemployment and prices.)

Today, bank runs are not a major problem for the banking system or the Fed. The federal government now guarantees the safety of deposits at most banks, primarily through the Federal Deposit Insurance Corporation (FDIC). Depositors do not run on their banks because they are confident that, even if their bank goes bankrupt, the FDIC will make good on the deposits. The

A NOT-SO-WONDERFUL

BANK RUN

Accumulated over so many years, a 5 percent annual inflation rate leads to an 18-fold increase in the price level.

Inflation may seem natural and inevitable to a person who grew up in the United States during the second half of the twentieth century, but in fact it is not inevitable at all. There were long periods in the nineteenth century during which most prices fell—a phenomenon called deflation. The average level of prices in the U.S. economy was 23 percent lower in 1896 than in 1880, and this deflation was a major issue in the presidential election of 1896. Farmers, who had accumulated large debts, were suffering when the fall in crop prices reduced their incomes and thus their ability to pay off their debts. They advocated government policies to reverse the deflation.

Although inflation has been the norm in more recent history, there has been substantial variation in the rate at which prices rise. During the 1990s, prices rose at an average rate of about 2 percent per year. By contrast, in the 1970s, prices rose by 7 percent per year, which meant a doubling of the price level over the decade. The public often views such high rates of inflation as a major economic problem. In fact, when President Jimmy Carter ran for reelection in 1980, challenger Ronald Reagan pointed to high inflation as one of the failures of Carter’s economic policy.

International data show an even broader range of inflation experiences. Germany after World War I experienced a spectacular example of inflation. The price of a newspaper rose from 0.3 marks in January 1921 to 70,000,000 marks less than two years later. Other prices rose by similar amounts. An extraordinarily high rate of inflation such as this is called hyperinflation. The German hyperinflation had such an adverse effect on the German economy that it is often viewed as one contributor to the rise of Nazism and, as a result, World War II. Over the past 50 years, with this episode still in mind, German policymakers have been extraordinarily averse to inflation, and Germany has had much lower inflation than the United States.

What determines whether an economy experiences inflation and, if so, how much? This chapter answers this question by developing the quantity theory of money. Chapter 1 summarized this theory as one of the Ten Principles of Economics: Prices rise when the government prints too much money. This insight has a long and venerable tradition among economists. The quantity theory was discussed by the famous eighteenth-century philosopher David Hume and has been advocated more recently by the prominent economist Milton Friedman. This theory of inflation can explain both moderate inflations, such as those we have experienced in the United States, and hyperinflations, such as those experienced in interwar Germany and, more recently, in some Latin American countries.

After developing a theory of inflation, we turn to a related question: Why is inflation a problem? At first glance, the answer to this question may seem obvious: Inflation is a problem because people don’t like it. In the 1970s, when the United States experienced a relatively high rate of inflation, opinion polls placed inflation as the most important issue facing the nation. President Ford echoed this sentiment in 1974 when he called inflation “public enemy number one.” Ford briefly wore a “WIN” button on his lapel—for “Whip Inflation Now.”

But what, exactly, are the costs that inflation imposes on a society? The answer may surprise you. Identifying the various costs of inflation is not as straightforward as it first appears. As a result, although all economists decry hyperinflation, some economists argue that the costs of moderate inflation are not nearly as large as the general public believes.

economy, it also misses a key point: Inflation is an economy-wide phenomenon that concerns, first and foremost, the value of the economy’s medium of exchange.

The economy’s overall price level can be viewed in two ways. So far, we have viewed the price level as the price of a basket of goods and services. When the price level rises, people have to pay more for the goods and services they buy. Alternatively, we can view the price level as a measure of the value of money. A rise in the price level means a lower value of money because each dollar in your wallet now buys a smaller quantity of goods and services.

It may help to express these ideas mathematically. Suppose P is the price level as measured, for instance, by the consumer price index or the GDP deflator. Then P measures the number of dollars needed to buy a basket of goods and services. Now turn this idea around: The quantity of goods and services that can be bought with $1 equals 1/P. In other words, if P is the price of goods and services measured in terms of money, 1/P is the value of money measured in terms of goods and services. Thus, when the overall price level rises, the value of money falls.

MONEY SUPPLY, MONEY DEMAND,

AND MONETARY EQUILIBRIUM

What determines the value of money? The answer to this question, like many in economics, is supply and demand. Just as the supply and demand for bananas determines the price of bananas, the supply and demand for money determines the value of money. Thus, our next step in developing the quantity theory of money is to consider the determinants of money supply and money demand.

First consider money supply. In the preceding chapter we discussed how the Federal Reserve, together with the banking system, determines the supply of money. When the Fed sells bonds in open-market operations, it receives dollars in exchange and contracts the money supply. When the Fed buys government bonds, it pays out dollars and expands the money supply. In addition, if any of these dollars are deposited in banks who then hold them as reserves, the money multiplier swings into action, and these open-market operations can have an even greater effect on the money supply. For our purposes in this chapter, we ignore the complications introduced by the banking system and simply take the quantity of money supplied as a policy variable that the Fed controls directly and completely.

Now consider money demand. There are many factors that determine the quantity of money people demand, just as there are many determinants of the quantity demanded of other goods and services. How much money people choose to hold in their wallets, for instance, depends on how much they rely on credit cards and on whether an automatic teller machine is easy to find. And, as we will emphasize in Chapter 32, the quantity of money demanded depends on the interest rate that a person could earn by using the money to buy an interest-bearing bond rather than leaving it in a wallet or low-interest checking account.

Although many variables affect the demand for money, one variable stands out in importance: the average level of prices in the economy. People hold money because it is the medium of exchange. Unlike other assets, such as bonds or stocks, people can use money to buy the goods and services on their shopping lists. How much money they choose to hold for this purpose depends on the prices of those goods and services. The higher prices are, the more money the typical transaction requires, and the more money people will choose to hold in their wallets and