Chapter 10(25)

1. THIRD EDITION ECONOMICS and MACROECONOMICSPaul Krugman | Robin Wells Chapter 10(25) Savings, Investment Spending, and the Financial System

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 WHAT YOU WILL LEARN IN THIS CHAPTER

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. Pitfalls 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.”

8. Pitfalls Investment versus Investment Spending • 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 called making an investment.

9. The Savings–Investment Spending Identity Capital inflows Private savings Private savings Budget deficit Capital outflows Budget deficit (b) Japan, 2007 (a) United States, 2007 Share of GDP Share of GDP 25% 20 15 10 5 0 –5 –10 –15 25% 20 15 10 5 0 –5 –10 –15 Investment spending Investment spending Savings Savings

10. GLOBAL COMPARISON: America’s Low Savings

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

12. Pitfalls 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.

13. FOR INQUIRING MINDS 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.

14. FOR INQUIRING MINDS Who Enforces the Accounting? • 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.

15. 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.

16. 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.

17. The Demand for Loanable Funds Interest rate A 12% B 4 Demand for loanable funds, D 0 450 $150 Quantity of loanable funds (billions of dollars)

18. The Supply for Loanable Funds 12% Y 450 Interest rate Supply of loanable funds, S 4 X $150 0 Quantity of loanable funds (billions of dollars)

19. Equilibrium in the Loanable Funds Market Interest rate Projects with rate of return 8% or greater are funded. 12% 8 4 0 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. Offers accepted from lenders willing to lend at interest rate of 8% or less. $300 Quantity of loanable funds (billions of dollars) Q*

20. 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.

21. r 2 . . . leads to a rise in the equilibrium interest rate. An Increase in the Demand for Loanable Funds Interest rate S An increase in the demand for loanable funds . . . r 1 D 2 D 1 Quantity of loanable funds

22. 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 United States 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 2006. As a result of the worldwide slump, those inflows began to trail off in 2008.

23. . . . leads to a fall in the equilibrium interest rate. r 2 An Increase in the Supply of Loanable Funds Interest rate S 1 S 2 r 1 An increase in the supply for loanable funds . . . D Quantity of loanable funds

24. 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.

25. 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.

26. 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.

27. 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.

28. The Fisher Effect Demand for loanable funds at 10% expected inflation Supply of loanable funds at 10% expected inflation Nominal Interest rate S 10 E 10 14% D Supply of loanable funds at 0% expected inflation Demand for loanable funds at 0% expected inflation 10 S 0 4 E 0 D 0 0 Quantity of loanable funds Q*

29. ECONOMICS IN ACTION Fifty Years of U.S. Interest Rates

30. FOR INQUIRING MINDS Using Present Value • To make investment decisions, we need to calculate how the value of a dollar in the future compares with the value of a dollar today. It’s always less—but how much less? • Another way to ask that question is: what is the present value of an expected future return?

31. The Concept of Present Value • When someone borrows money for a year, the interest rate is the price, calculated as a percentage of the amount borrowed, charged by the lender. • The interest rate can be used to compare the value of a dollar realized today with the value of a dollar realized later, because it correctly measures the cost of delaying a dollar of benefit (and the benefit of delaying a dollar of cost). • The present value of $1 realized one year from now is equal to $1/(1 + r): the amount of money you must lend out today in order to have $1 in one year. It is the value to you today of $1 realized one year from now.

32. Present Value • Let’s call $V the amount of money you need to lend today, at an interest rate of r in order to have $1 in two years. • So if you lend $V today, you will receive $V(1 + r) in one year. • And if you re-lend that sum for yet another year, you will receive $V × (1 + r) × (1 + r) = $V × (1 + r)2 at the end of the second year. • At the end of two years, $V will be worth $V × (1 + r)2 • If r = 0.10, then this becomes $V × (1.10)2 = $V × (1.21).

33. Present Value • What is $1 realized two years in the future worth today? • In order for the amount lent today, $V, to be worth $1 two years from now, it must satisfy this formula: $V × (1 + r)2 = $1 • If r = 0.10, $V = $1/(1 + r)2 = $1/1.21 = $0.83 • The present value formula is equal to $1/(1 + r) N

34. Net Present Value The net present value of a project is the present value of current and future benefits minus the present value of current and future costs.

35. 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.

36. 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.

37. 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).

38. 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.

39. 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.

40. 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.

41. 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.

42. 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.

43. An Example of a Diversified Mutual Fund

44. ECONOMICS IN ACTION 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.

45. ECONOMICS IN ACTION Banks and the South Korean Miracle • 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.

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

47. 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.

48. 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.

49. FOR INQUIRING MINDS 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.

50. FOR INQUIRING MINDS How Now, Dow Jones? • 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.