1. chapter: 26
>>
Savings, Investment Spending, and the Financial System
Krugman/Wells
©2009  Worth Publishers 1

2. The relationship between savings and investment spending
Aspects of the loanable funds market, which shows how savers are matched with borrowers
The purpose of the five principal types of assets: stocks, bonds, loans, real estate and bank deposits
How financial intermediaries help investors achieve diversification
Some competing views of what determines stock prices and why stock market fluctuations can be a source of macroeconomic instability

3. Matching Up Savings and Investment Spending
According to the savings–investment spending identity, savings and investment spending are always equal for the economy as a whole.
The budget surplus is the difference between tax revenue and government spending when tax revenue exceeds government spending.
The budget deficit is the difference between tax revenue and government spending when government spending exceeds tax revenue.

4. Matching Up Savings and Investment Spending
The budget balance is the difference between tax revenue and government spending.
National savings, the sum of private savings plus the budget balance, is the total amount of savings generated within the economy.
Capital inflow is the net inflow of funds into a country.

5. The Savings–Investment Spending Identity
In a simplified economy:
(1) Total Income = Total Spending
(2) Total income = Consumption spending + Savings
Meanwhile, spending consists of either consumption spending or investment spending:
(3) Total spending = Consumption spending + Investment spending
Putting these together, we get:
(4) Consumption spending + Savings = Consumption spending + Investment spending
Subtract consumption spending from both sides, and we get:
(5) Savings = Investment spending

6. The Savings–Investment Spending Identity
In a simplified economy:
GDP = C + I + G
SPrivate = GDP + TR − T − C
SGovernment = T − TR − G
NS = SPrivate + SGovernment = (GDP + TR − T − C) + (T − TR − G)
= GDP − C − G
Hence, I = NS
Investment spending = National savings in a closed economy

7. Investment versus investment spending
When macroeconomists use the term investment spending, they almost always mean “spending on new physical capital.” This can be confusing, because in ordinary life we often say that someone who buys stocks or purchases an existing building is “investing.”
The important point to keep in mind is that only spending that adds to the economy’s stock of physical capital is “investment spending.” In contrast, the act of purchasing an asset such as a share of stock, a bond, or existing real estate is “making an investment.”

8. The Savings–Investment Spending Identity
(a) United States
(b) Japan
Share
of GDP
Share
of GDP
25% 20 15 10 5 –5
–10
–15
25% 20 15 10 5 –5
–10
–15
Capital inflows
Private savings
Private savings
Budget deficit
Capital outflows
Investment spending
Investment spending
Savings
Savings
Budget deficit
Figure Caption: Figure 26-1: The Savings–Investment Spending Identity in Open Economies: the United States
and Japan, 2007
U.S. investment spending in 2007 (equal to 18.8% of GDP) was financed by a combination of private savings (15.7% of GDP) and capital inflows (5.2% of GDP), which were partially offset by a budget deficit (−1.6% of GDP). Japanese investment spending in 2007 was higher as a percentage of GDP (23.8%). It was financed by a higher level of private savings as a percentage of GDP (32.1%), which was offset by both a
capital outflow (−4.9% of GDP) and a relatively high budget deficit (−3.4% of GDP).
Source: Bureau of Economic Analysis; OECD. 8

9. The Savings–Investment Spending Identity
Investment spending = National savings + Capital inflow in an open economy
I = SPrivate + SGovernment + (IM − X) = NS + KI

10. The different kinds of capital
It’s important to understand clearly the three different kinds of capital: physical capital, human capital, and financial capital.
Physical capital consists of manufactured resources such as buildings and machines.
Human capital is the improvement in the labor force generated by education and knowledge.
Financial capital is funds from savings that are available for investment spending.
So a country that has a positive capital inflow is experiencing a flow of funds into the country from abroad that can be used for investment spending.

11. Who Enforces the Accounting?
The savings–investment spending identity is a fact of accounting. By definition, savings equals investment spending for the economy as a whole. But who enforces the arithmetic?
The short answer is that actual and desired investment spending aren’t always equal. Suppose that households suddenly decide to save more by spending less. The immediate effect will be that unsold goods pile up. And this increase in inventory counts as investment spending, albeit unintended. So the savings–investment spending identity still holds.
Similarly, if households suddenly decide to save less and spend more, inventories will drop—and this will be counted as negative investment spending.

12. The Market for Loanable Funds
The loanable funds market is a hypothetical market that examines the market outcome of the demand for funds generated by borrowers and the supply of funds provided by lenders.
The interest rate is the price, calculated as a percentage of the amount borrowed, charged by the lender to a borrower for the use of their savings for one year.

13. The Market for Loanable Funds
The rate of return on a project is the profit earned on the project expressed as a percentage of its cost.

14. The Demand for Loanable Funds
Interest rate
12% 4
Figure Caption: Figure 26-2: The Demand for Loanable Funds
The demand curve for loanable funds slopes downward: the lower the interest rate, the greater the quantity of loanable funds demanded. Here, reducing the interest rate from 12% to 4% increases the quantity of loanable funds demanded from $150 billion to $450 billion.
Demand for loanable funds, D $
Quantity of loanable funds
(billions of dollars)

15. The Supply for Loanable Funds
Interest rate
Supply of loanable funds, S
12% 4
Figure Caption: Figure 26-3: The Supply of Loanable Funds
The supply curve for loanable funds slopes upward: the higher the interest rate, the greater the quantity of loanable funds supplied. Here, increasing the interest rate from 4% to 12% increases the quantity of loanable funds supplied from $150 billion to $450 billion. $
Quantity of loanable funds
(billions of dollars)

16. Equilibrium in the Loanable Funds Market
Interest rate
Projects with rate of return
8% or greater are funded.
12% 8 4
Offers not accepted from
lenders who demand interest
rate of more than 8%. r*
Projects with rate of return
less than 8% are not funded.
Figure Caption: Figure 26-4: Equilibrium in the Loanable Funds Market
At the equilibrium interest rate, the quantity of loanable funds supplied equals the quantity of loanable funds demanded. Here, the equilibrium interest rate is 8%, with $300 billion of funds lent and borrowed. Investment spending projects with a rate of return of 8% or higher receive funding; those with a lower rate of return do not. Lenders who demand an interest rate of 8% or lower have their offers of loans accepted; those who demand a higher interest rate do not.
Offers accepted from
lenders willing to lend at
interest rate of 8% or less.
$300
Quantity of loanable funds
(billions of dollars) Q*

17. Shifts of the Demand for Loanable Funds
Factors that can cause the demand curve for loanable funds to shift include:
Changes in perceived business opportunities
Changes in the government’s borrowing
Crowding out occurs when a government deficit drives up the interest rate and leads to reduced investment spending.

18. An Increase in the Demand for Loanable Funds
Interest rate r2 r1
. . . leads to
a rise in the
equilibrium
interest rate.
An increase
in the demand
for loanable
funds . . .
Figure Caption: Figure 26-5: An Increase in the Demand for Loanable Funds
If the quantity of funds demanded by borrowers rises at any given interest rate, the demand for loanable funds shifts rightward from D1 to D2. As a result, the equilibrium interest rate rises from r1 to r2.
Quantity of loanable funds
(billions of dollars) 18

19. Shifts of the Supply for Loanable Funds
Factors that can cause the supply of loanable funds to shift include:
Changes in private savings behavior: Between 2000 and 2006 rising home prices in the United States made many homeowners feel richer, making them willing to spend more and save less This shifted the supply of loanable funds to the left.
Changes in capital inflows: The U.S. has received large capital inflows in recent years, with much of the money coming from China and the Middle East. Those inflows helped fuel a big increase in residential investment spending from 2003 to As a result of the worldwide slump, those inflows began to trail off in 2008.

20. An Increase in the Supply of Loanable Funds
Interest rate r1 r2
An increase
in the supply of loanable
funds . . .
. . . leads to
a fall in the
equilibrium
interest rate.
Figure Caption: Figure 26-6: An Increase in the Supply of Loanable Funds
If the quantity of funds supplied by lenders rises at any given interest rate, the supply of loanable funds shifts rightward from S1 to S2. As a result, the equilibrium interest rate falls from r1 to r2.
Quantity of loanable funds
(billions of dollars) 20

21. Inflation and Interest Rates
Anything that shifts either the supply of loanable funds curve or the demand for loanable funds curve changes the interest rate.
Historically, major changes in interest rates have been driven by many factors, including:
changes in government policy.
technological innovations that created new investment opportunities.

22. Inflation and Interest Rates
However, arguably the most important factor affecting interest rates over time is changing expectations about future inflation.
This shifts both the supply and the demand for loanable funds.
This is the reason, for example, that interest rates today are much lower than they were in the late 1970s and early 1980s.

23. Inflation and Interest Rates
Real interest rate =
nominal interest rate - inflation rate
In the real world neither borrowers nor lenders know what the future inflation rate will be when they make a deal. Actual loan contracts, therefore, specify a nominal interest rate rather than a real interest rate.

24. The Fisher Effect
According to the Fisher effect, an increase in expected future inflation drives up the nominal interest rate, leaving the expected real interest rate unchanged.

25. The Fisher Effect Nominal interest rate S10 E10 D10 S0 E0 D0 14% 4 Q*
D10 S0
Figure Caption: Figure 26-7: The Fisher Effect
D0 and S0 are the demand and supply curves for loanable funds when the expected future inflation rate is 0%. At an expected inflation rate of 0%, the equilibrium nominal interest rate is 4%. An increase in expected future inflation pushes both the demand and supply curves upward by 1 percentage point for every percentage point increase in expected future inflation. D10 and S10 are the demand and supply curves for loanable funds when the expected future inflation rate is 10%. The 10 percentage point increase in expected future inflation raises the equilibrium nominal interest rate to 14%. The expected real interest rate remains at 4%, and the equilibrium quantity of loanable funds also remains unchanged. E0 D0 Q*
Quantity of loanable funds 25

26. Changes in the U.S. Interest Rates Over Time
(a) Changes in Expected Inflation and Interest Rates
(b) Changes in Expected Rate of Return on Investment Spending and Interest Rates
10-Year Treasury constant maturity rate, inflation rate
10-Year Treasury constant maturity rate 7% 6 5 4 3
16% 14 12 10 8 6 4 2
Figure Caption: Figure 26-8: Changes in U.S. Interest Rates Over Time
As panel (a) shows, high current inflation leads to expectations of high future inflation, which results in a rise in the interest rate. Panel (b) shows the effect of changes in the expected return on investment spending on interest rates. During 1998–2008, expectations of future inflation were relatively constant, but the interest rate first rose and then fell sharply. The rise and eventual decline were driven mainly by the boom and then bust in high-technology investment spending.
Source: Federal Reserve Bank of St. Louis; Bureau of Labor Statistics.
Year
Year

27. The Financial System
A household’s wealth is the value of its accumulated savings.
A financial asset is a paper claim that entitles the buyer to future income from the seller.
A physical asset is a claim on a tangible object that gives the owner the right to dispose of the object as he or she wishes.

28. The Financial System
A liability is a requirement to pay income in the future.
Transaction costs are the expenses of negotiating and executing a deal.
Financial risk is uncertainty about future outcomes that involve financial losses and gains.

29. The Financial System (a) Typical Individual (b) Wealthy Individual
Change in individual welfare
Change in individual welfare
Wealth gain from gaining $1,000
Wealth gain from gaining $1,000
$1,000
–2,000
$1,000
–1,200
Figure Caption: Figure 26-9: Risk-Averse Attitudes Toward Gain and Loss
A comparison of panels (a) and (b) shows that differences in wealth lead to differences in attitudes toward risk. The typical individual represented in panel (a) experiences a $1,000 loss as a much more significant hardship than the wealthy individual represented in panel (b). This reflects the fact that wealthy individuals, although still risk-averse, tend to be more tolerant of risk than individuals of modest means.
Wealth loss from losing $1,000
Wealth loss from losing $1,000

30. Three Tasks of a Financial System
Reducing transaction costs ─ the cost of making a deal.
Reducing financial risk ─ uncertainty about future outcomes that involves financial gains and losses.
Providing liquid assets ─ assets that can be quickly converted into cash (in contrast to illiquid assets, which can’t).

31. Three Tasks of a Financial System
An individual can engage in diversification by investing in several different things so that the possible losses are independent events.
An asset is liquid if it can be quickly converted into cash.
An asset is illiquid if it cannot be quickly converted into cash.

32. Types of Financial Assets
There are four main types of financial assets:
loans
bonds
stocks
bank deposits
In addition, financial innovation has allowed the creation of a wide range of loan-backed securities.

33. Types of Financial Assets
A loan is a lending agreement between a particular lender and a particular borrower.
A default occurs when a borrower fails to make payments as specified by the loan or bond contract.
A loan-backed security is an asset created by pooling individual loans and selling shares in that pool.

34. Financial Intermediaries
A financial intermediary is an institution that transforms the funds it gathers from many individuals into financial assets.
A mutual fund is a financial intermediary that creates a stock portfolio and then resells shares of this portfolio to individual investors.
A pension fund is a type of mutual fund that holds assets in order to provide retirement income to its members.

35. Financial Intermediaries
A life insurance company sells policies that guarantee a payment to a policyholder’s beneficiaries when the policyholder dies.
A bank deposit is a claim on a bank that obliges the bank to give the depositor his or her cash when demanded.
A bank is a financial intermediary that provides liquid assets in the form of bank deposits to lenders and uses those funds to finance the illiquid investments or investment spending needs of borrowers.

36. An Example of a Diversified Mutual Fund
Fidelity Spartan S&P 500 Index Fund, Top Holdings (as of September 2008)
Company
Percent of mutual fund assets invested in a company
Exxon Mobil
3.96%
General Electric
2.49
Procter & Gamble
2.08
Microsoft
2.06
Johnson & Johnson
1.90
JPMorgan Chase
1.69
Chevron
1.66
AT&T
1.62
Bank of America
1.57
IBM
1.56
Source: Fidelity Investments

37. Banks and the South Korean Miracle
In the early 1960s, South Korea’s interest rates on deposits were very low at a time when the country was experiencing high inflation. So savers didn’t want to save by putting money in a bank, fearing that much of their purchasing power would be eroded by rising prices. Instead, they engaged in current consumption by spending their money on goods and services or on physical assets such as real estate and gold.
In 1965 the South Korean government reformed the country’s banks and increased interest rates. Over the next five years the value of bank deposits increased 600% and the national savings rate more than doubled. The rejuvenated banking system made it possible for South Korean businesses to launch a great investment boom, a key element in the country’s growth surge.

38. Financial Fluctuations
Financial market fluctuations can be a source of macroeconomic instability.
Stock prices are determined by supply and demand as well as the desirability of competing assets, like bonds:
when the interest rate rises, stock prices generally fall and vice versa.

39. Financial Fluctuations
The value of a financial asset today depends on investors’ beliefs about the future value or price of the asset.
If investors believe that it will be worth more in the future, they will demand more of the asset today at any given price.
Consequently, today’s equilibrium price of the asset will rise.

40. Financial Fluctuations
If investors believe the asset will be worth less in the future, they will demand less today at any given price.
Consequently, today’s equilibrium price of the asset will fall.
Today’s stock prices will change according to changes in investors’ expectations about future stock prices.

41. How Now, Dow Jones?
Financial news reports often lead with the day’s stock market action, as measured by changes in the Dow Jones Industrial Average, the S&P 500, and the NASDAQ. All three are stock market indices. Like the consumer price index, they are numbers constructed as a summary of average prices.
The Dow, created by the financial analysis company Dow Jones, is an index of the prices of stock in 30 leading companies, The S&P 500 is an index of 500 companies, created by Standard and Poor’s. The NASDAQ is compiled by the National Association of Securities Dealers.
The movement in an index gives investors a quick, snapshot view of how stocks from certain sectors of the economy are doing.

42. Financial Fluctuations
Financial market fluctuations can be a source of macroeconomic instability.
There are two principal competing views about how asset price expectations are determined.
One view, which comes from traditional economic analysis, emphasizes the rational reasons why expectations should change.
The other, widely held by market participants and also supported by some economists, emphasizes the irrationality of market participants.

43. Financial Fluctuations
One view of how expectations are formed is the efficient markets hypothesis, which holds that the prices of financial assets embody all publicly available information.
It implies that fluctuations are inherently unpredictable—they follow a random walk.

44. Irrational Markets?
Many market participants and economists believe that, based on actual evidence, financial markets are not as rational as the efficient markets hypothesis claims.
Such evidence includes the fact that stock price fluctuations are too great to be driven by fundamentals alone.

45. Asset Prices and Macroeconomics
How do macroeconomists and policy makers deal with the fact that asset prices fluctuate a lot and that these fluctuations can have important economic effects?
Should policy makers try to pop asset bubbles before they get too big?
This debate covered in chapter 17.

46. The S&P 500 Index from October 1982 to April 2005
Optional slide (from earlier edition):
From 1982 to 1995 the stock market rose steadily with only a few setbacks, the most notable being the 1987 crash. In 1995, however, the market began growing at a much faster pace, and in 1996 Alan Greenspan cautioned that the market might be suffering from “irrational exuberance.”
The market, however, continued to rise for another four years—until 2000, when stock prices in general, and the prices of technology stocks in particular, suffered a large fall.

47. The Great American Housing Bubble
Between 2000 and 2006, there was a huge increase in the price of houses in America. A number of economists argued that this price increase was excessive—that it was a “bubble”.
Yet there were also a number of economists who argued that the rise in housing prices was completely justified.
They pointed, in particular, to the fact that interest rates were unusually low in the years of rapid price increases.
They argued that low interest rates combined with other factors, such as growing population, explained the surge in prices.

48. The Great American Housing Bubble
Alan Greenspan, the chairman of the Federal Reserve, conceded in 2005 that there might be some “froth” in the markets but denied that there was any national bubble.
Unfortunately, it turned out that the skeptics were right. Greenspan himself would later concede that there had, in fact, been a huge national bubble.
In 2006, as home prices began to level off, it became apparent that many buyers had held unrealistic expectations about future prices.
Home prices began falling, and the demand for housing fell drastically.

49. The Great American Housing Bubble
New
single-family
houses sold
(thousands)
Index
(2000 = 100)
220
200
180
160
140
120
100 80
1,400
1,200
1,000
800
600
Figure Caption: Figure 26-10: The Great American Housing Bubble
Panel (a) shows the average prices of U.S. houses compared with an estimate of average rents, both expressed as index numbers with January 2000 = 100. There was a large run-up in home prices after 2000, which some economists argued was not justified by fundamentals. Others disagreed, but by 2007 it was clear that there had indeed been a bubble driven by unrealistic expectations about future prices. When expectations of rising prices turned into expectations of falling prices, the demand for homes slumped. Panel (b) shows new sales of single-family homes, which reached record levels during the mid-2000s, then fell steeply.
Source: Panel (a): Standard and Poor’s; Bureau of Labor Statistics,
Panel (b): Federal Reserve Bank of St. Louis.
Year
Year

50. Investment in physical capital is necessary for long-run economic growth. So in order for an economy to grow, it must channel savings into investment spending.
According to the savings–investment spending identity, savings and investment spending are always equal for the economy as a whole. The government is a source of savings when it runs a positive budget balance or budget surplus; it is a source of dissavings when it runs a negative budget balance or budget deficit. In a closed economy, savings is equal to national savings, the sum of private savings plus the budget balance. In an open economy, savings is equal to national savings plus capital inflow of foreign savings. When a capital outflow, or negative capital inflow, occurs, some portion of national savings is funding investment spending in other countries.

51. The hypothetical loanable funds market shows how loans from savers are allocated among borrowers with investment spending projects. In equilibrium, only those projects with a rate of return greater than or equal to the equilibrium interest rate will be funded. By showing how gains from trade between lenders and borrowers are maximized, the loanable funds market shows why a well functioning financial system leads to greater long-run economic growth. Government budget deficits can raise the interest rate and can lead to crowding out of investment spending. Changes in perceived business opportunities and in government borrowing shift the demand curve for loanable funds; changes in private savings and capital inflows shift the supply curve.

52. Because neither borrowers nor lenders can know the future inflation rate, loans specify a nominal interest rate rather than a real interest rate. For a given expected future inflation rate, shifts of the demand and supply curves of loanable funds result in changes in the underlying real interest rate, leading to changes in the nominal interest rate. According to the Fisher effect, an increase in expected future inflation raises the nominal interest rate one-to-one so that the expected real interest rate remains unchanged.

53. Households invest their current savings or wealth by purchasing assets
Households invest their current savings or wealth by purchasing assets. Assets come in the form of either a financial asset or a physical asset. A financial asset is also a liability from the point of view of its seller. There are four main types of financial assets: loans, bonds, stocks, and bank deposits. Each of them serves a different purpose in addressing the three fundamental tasks of a financial system: reducing transaction costs—the cost of making a deal; reducing financial risk—uncertainty about future outcomes that involves financial gains and losses; and providing liquid assets— assets that can be quickly converted into cash without much loss of value (in contrast to illiquid assets, which are not easily converted).

54. Although many small and moderate-size borrowers use bank loans to fund investment spending, larger companies typically issue bonds. Bonds with a higher risk of default must typically pay a higher interest rate. Business owners reduce their risk by selling stock. Although stocks usually generate a higher return than bonds, investors typically wish to reduce their risk by engaging in diversification, owning a wide range of assets whose returns are based on unrelated, or independent, events. Most people are risk-averse. Loan-backed securities, a recent innovation, are assets created by pooling individual loans and selling shares of that pool to investors. Because they are more diversified and more liquid than individual loans, trading on financial markets like bonds, they are preferred by investors. It can be difficult, however, to assess their quality.

55. Financial intermediaries—institutions such as mutual funds, pension funds, life insurance companies, and banks—are critical components of the financial system. Mutual funds and pension funds allow small investors to diversify, and life insurance companies reduce risk.
A bank allows individuals to hold liquid bank deposits that are then used to finance illiquid loans. Banks can perform this mismatch because on average only a small fraction of depositors withdraw their savings at any one time. Banks are a key ingredient of long-run economic growth.

56. Asset market fluctuations can be a source of short-run macroeconomic instability. Asset prices are determined by supply and demand as well as by the desirability of competing assets, like bonds: when the interest rate rises, prices of stocks and physical assets such as real estate generally fall, and vice versa. Expectations drive the supply of and demand for assets: expectations of higher future prices push today’s asset prices higher, and expectations of lower future prices drive them lower. One view of how expectations are formed is the efficient markets hypothesis, which holds that the prices of assets embody all publicly available information. It implies that fluctuations are inherently unpredictable—they follow a random walk.

57. Many market participants and economists believe that, based on actual evidence, financial markets are not as rational as the efficient markets hypothesis claims. Such evidence includes the fact that stock price fluctuations are too great to be driven by fundamentals alone. Policy makers assume neither that markets always behave rationally nor that they can outsmart them.

58. coming attraction: Chapter 27: Income and Expenditure
The End of Chapter 26
coming attraction: Chapter 27: Income and Expenditure