5 Measuring GDP and Economic Growth

5 Measuring GDP and Economic Growth
CHAPTER Measuring GDP and Economic Growth Notes and teaching tips: 4, 26, 36, 46, 59, 62, and 65. To view a full-screen figure during a class, click the red “expand” button. To return to the previous slide, click the red “shrink” button. To advance to the next slide, click anywhere on the full screen figure.

An Economic Barometer What exactly is GDP? How do we use GDP to tell us whether our economy is in a recession or how rapidly our economy is expanding? How do we take the effects of inflation out of GDP to reveal the rate of growth of our economic well-being? And how to we compare economic well-being across countries?

Gross Domestic Product
GDP Defined GDP or gross domestic product is the market value of all final goods and services produced in a country in a given time period. This definition has four parts: Market value Final goods and services Produced within a country In a given time period The main challenge in teaching this topic is generating interest in it. Many teachers are bored by it and not surprisingly, they bore their students. If you are one of the many who lean toward boredom, start by recalling just how vital it is that we measure the value of production with reasonable accuracy. For such a measure is the basis of measurement of the standard of living, economic welfare, and making international comparisons. Final goods versus intermediate goods. The distinction between final and intermediate goods is one of the key points in this first section. Use some standard examples to make the key point—tires and autos, chips and computers, and so on. Also, if you want to spend a bit of time on this topic, tell your students about the Bureau of Economic Analysis (BEA) revision in the treatment of business spending on software. The BEA began a major revision in 1998 and published the first revisions to reclassify software from intermediate to final good status in 1999. When the 1996 GDP was recalculated to include software, it increased by $115 billion, or 1.5 percent of GDP.

Market Value GDP is a market value—goods and services are valued at their market prices. To add apples and oranges, computers and popcorn, we add the market values so we have a total value of output in dollars.

Final Goods and Services GDP is the value of the final goods and services produced. A final good (or service) is an item bought by its final user during a specified time period. A final good contrasts with an intermediate good, which is an item that is produced by one firm, bought by another firm, and used as a component of a final good or service. Excluding intermediate goods and services avoids double counting.

Produced Within a Country GDP measures production within a country—domestic production. In a Given Time Period GDP measures production during a specific time period, normally a year or a quarter of a year.

GDP and the Circular Flow of Expenditure and Income GDP measures the value of production, which also equals total expenditure on final goods and total income. The equality of income and output shows the link between productivity and living standards. The circular flow diagram in Fig. 5.1 illustrates the equality of income, expenditure, and the value of production.

The circular flow diagram shows the transactions among households, firms, governments, and the rest of the world.

These transactions take place in factor markets, goods markets, and financial markets.

Firms hire factors of production from households. The blue flow, Y, shows total income paid by firms to households.

Households buy consumer goods and services. The red flow, C, shows consumption expenditure.

Households save, S, and pay net taxes, T. Firms borrow some of what households save to finance their investment.

Firms buy capital goods from other firms. The red flow I represents this investment by firms.

Governments buy goods and services, G, and borrow or repay debt if spending exceeds or is less than net taxes.

The rest of the world buys goods and services from us, X, and sells us goods and services, M. Net exports are X – M.

And the rest of the world borrows from us or lends to us depending on whether net exports are positive or negative.

The blue and red flows are the circular flow of expenditure and income. The green flows are financial flows.

The sum of the red flows equals the blue flow.

That is: Y = C + I + G + X – M

The circular flow demonstrates how GDP can be measured in two ways. Aggregate expenditure Total expenditure on final goods and services, equals the value of output of final goods and services, which is GDP. Total expenditure = C + I + G + (X – M).

Aggregate income Aggregate income equals the total amount paid for the use of factors of production: wages, interest, rent, and profit. Firms pay out all their receipts from the sale of final goods, so income equals expenditure, Y = C + I + G + (X – M).

Financial Flows Flows through financial markets finance deficits and investment. Household saving S is income minus net taxes and consumption expenditure. That is, S = Y – (T + C). Saving flows into the financial markets.

If G exceeds T, the government has a budget deficit (G –T) and the government borrows from the financial markets. If T exceeds G, the government has a budget surplus (T – G) and this surplus flows to the financial markets. If U.S. imports exceed U.S. exports, the United States borrows an amount equal to (M – X) from the rest of the world. Rest of world saving finances some investment in the United States. If U.S. exports exceed U.S. imports, the United States lends an amount equal to (X – M) to the rest of the world. U.S. saving finances some investment in other countries.

How Investment Is Financed Investment is financed from three sources: 1. Private saving, S 2. Government budget surplus, (T – G) 3. Borrowing from the rest of the world (M – X). How investment is financed. Don’t skimp on this topic. It provides the foundation for what the student will meet in Chapter 23 (Economics) Chapter 7 (Macroeconomics).

We can see these three sources of investment finance by using the equality of aggregate expenditure and aggregate income. Start with Y = C + S + T = C + I + G + (X – M). Then rearrange to obtain I = S + (T – G) + (M – X) Private saving S plus government saving (T – G) is called national saving.

Gross and Net Domestic Product “Gross” means before deducting the depreciation of capital. The opposite of gross is net. To understand this distinction, we need to distinguish between flows and stocks. Flows and Stocks in Macroeconomics A flow is a quantity per unit of time. A stock is the quantity that exists at a point in time.

Wealth and Saving Wealth, the value of all the things that people own, is a stock. Saving is the flow that changes the stock of wealth. Wealth at the start of this year equals wealth at the start of last year plus saving during last year.

Capital and Investment Capital is the plant, equipment, and inventories of raw and semi-finished materials that are used to produce other goods. Capital is a stock. Investment is the flow that changes the stock of capital.

Depreciation is the decrease in the capital stock that results from wear and tear and obsolescence. Gross investment is the total amount spent on purchases of new capital and on replacing depreciated capital. Net investment is the change in the capital stock. Net investment = Gross investment  Depreciation.

Figure 5.2 illustrates the relationships among the capital stock, gross investment, depreciation, and net investment.

Back to Gross in GDP Gross profits, and GDP, include depreciation. Similarly, gross investment includes that amount of purchases of new capital goods that replace depreciation. Net profits, net domestic product, and net investment subtract depreciation from the gross concepts.

The Short Run Meets the Long Run Capital and investment play a central role in the understanding the growth and fluctuations in real GDP. Investment adds to the capital stock, so investment is one source of real GDP growth. Investment fluctuates, so investment is one source of fluctuations in real GDP.

Measuring U.S. GDP The Bureau of Economic Analysis uses two approaches to measure GDP: The expenditure approach The income approach The low cost of economic data. You might like to tell your students that measuring real GDP is actually very cheap. The Bureau of Economic Analysis (in the Department of Commerce) employs fewer than 500 economists, accountants, statisticians, and IT specialists at an annual cost of less that $70 million. It costs each American less than a quarter to measure the value of US production. For some further perspective, the U.S. National Oceanic and Atmospheric Administration, whose mission is to “describe and predict changes in the Earth’s environment, and conserve and manage wisely the nation’s coastal and marine resources so as to ensure sustainable economic opportunities,” employs more than 11,000 scientists and support personnel at an annual cost of $3.2 billion! Much of the income data used by the BEA comes from the Internal Revenue Service. Expenditure data comes from a variety of sources. Creative accounting and GDP measurement. In recent years, the first estimates of GDP, which are based on companies’ reported profits, have been revised downward when data on company profits as reported to the IRS became available. Enron-style accounting has contaminated the initial estimates of GDP, but not the final estimates. You can make a nice point with one example of creative accounting. For some years, in its reports to stock holders AOL recorded its advertising expenditure as investment and amortized it over a number of years. First, you can explain that the correct treatment of this item is as an expenditure on intermediate goods and services by AOL and as a charge against AOL profit. The expenditure on AOL services is the value of AOL’s production. And AOL’s expenditure on advertising is part of the value of the production of the advertising agencies used by AOL. You can go on to explain that AOL accounting practice would misleadingly swell GDP by causing some double counting. On the expenditure approach, AOL’s advertising expenditure shows up as investment in the national accounts. On the income approach, because the expenditure is not a cost, it swells profit, so AOL’s corporate profit increases by the same amount as its “investment.” If AOL filed its income tax return in this same way, the national income accounts wouldn’t get corrected. But if when AOL files its tax returns it calls its advertising a cost and lowers its profits by that amount, the BEA picks up these numbers from the IRS and the national accounts get adjusted appropriately.

Measuring U.S. GDP The Expenditure Approach
The expenditure approach measures GDP as the sum of consumption expenditure, investment, government expenditure on goods and services, and net exports. GDP = C + I + G + (X  M) Table 5.1 in the textbook shows the expenditure approach with data for 2006. GDP = $9,079 + $2,215 + $2,479  $765 = $13,008

Measuring U.S. GDP The Income Approach
The income approach measures GDP by summing the incomes that firms pay households for the factors of production they hire.

Measuring U.S. GDP The National Income and Expenditure Accounts divide incomes into five categories: 1. Compensation of employees 2. Net interest 3. Rental income 4. Corporate profits 5. Proprietors’ income These five income components sum to net domestic income at factor cost.

Measuring U.S. GDP Two adjustments must be made to get GDP:
1. Indirect taxes minus subsidies are added to get from factor cost to market prices. 2. Depreciation (or capital consumption) is added to get from net domestic product to gross domestic product. Table 5.2 in the textbook shows the income approach with data for 2006.

Real GDP and the Price Level
Real GDP is the value of final goods and services produced in a given year when valued at constant prices. Calculating Real GDP The first step in calculating real GDP is to calculate nominal GDP. Nominal GDP is the value of goods and services produced during a given year valued at the prices that prevailed in that same year.

Nominal GDP Calculations The table provides data for 2005 and 2006. In 2005, Expenditure on balls = $100 Expenditure on bats = $100 Nominal GDP = $200 Item Quantity Price 2005 Balls 100 $1.00 Bats 20 $5.00 2006 160 $0.50 22 $22.50

In 2006, Expenditure on balls = $80 Expenditure on bats = $495 Nominal GDP = $575 Item Quantity Price 2005 Balls 100 $1.00 Bats 20 $5.00 2006 160 $0.50 22 $22.50

Base-Year Prices Value of Real GDP This method of calculating real GDP is to value each year’s output at the prices of a base year. In the base year, real GDP equals nominal GDP. Suppose 2005 is the base year, then real GDP in 2005 is $200. This method is the traditional method. Item Quantity Price 2005 Balls 100 $1.00 Bats 20 $5.00 2006 160 $0.50 22 $22.50

Using the traditional base-year prices method to calculate real GDP in 2006: Expenditure on balls in 2006 valued at 2005 prices is $160. Expenditure on bats in 2006 valued at 2005 prices is $110. So real GDP in 2006 would be recorded as $270. Item Quantity Price 2005 Balls 100 $1.00 Bats 20 $5.00 2006 160 $0.50 22 $22.50

The new method of calculating real GDP, which is called the chain-weighted output index. The chain-weighted output index method, uses the prices of two adjacent years to calculate the real GDP growth rate. This calculation has four steps described on the next slide. Chain-weighted output index method. If you don’t want to bother with the chain-weighted output index method of calculating real GDP and prefer to limit your discussion to the traditional base-year prices method, you can draw a line half way down the first column of page 492 (Economics) page 120 (Macroeconomics) and define the number we compute in Table 5.5 as real GDP. The section on calculating the price level flows fine with this measure of real GDP. But I suggest that you do explain the chain-weighted method. The textbook has stripped the explanation down to the bare bones and makes the approach intelligible to any student willing to make a small amount of effort.

Step 1: Value last year’s production and this year’s production at last year’s prices and then calculate the growth rate of this number from last year to this year. Step 2: Value last year’s production and this year’s production at this year’s prices and then calculate the growth rate of this number from last year to this year. Step 3: Calculate the average of the two growth rates. This average growth rate is the growth rate of real GDP from last year to this year. Step 4: Apply the growth rate this year to last year’s real GDP to calculate this year’s real GDP.

We’ve done step 1. Value of 2005 quantities at 2005 prices (GDP in 2005) is $200. Value of 2006 quantities at 2005 prices is $270. At 2005 prices, the value of production increased from $200 to $270—an increase of 35 percent. Item Quantity Price 2005 Balls 100 $1.00 Bats 20 $5.00 2006 160 $0.50 22 $22.50

Step 2. Value of 2005 quantities at 2006 prices is $500. Value of 2006 quantities at 2006 prices (GDP in 2006) is $575. At 2006 prices, the value of production increased from $500 to $575—an increase of 15 percent. Item Quantity Price 2005 Balls 100 $1.00 Bats 20 $5.00 2006 160 $0.50 22 $22.50

Step 3. At 2005 prices, the 2006 growth rate is 35 percent. At 2006 prices, the 2006 growth rate is 15 percent. The average of these two growth rates is 25 percent. Item Quantity Price 2005 Balls 100 $1.00 Bats 20 $5.00 2006 160 $0.50 22 $22.50

Step 4. So with 2005 as the base year, real GDP in 2006 is $250—25 percent more that $200 in 2005. Real GDP in 2005 is $200 Real GDP in 2006 is $250 Item Quantity Price 2005 Balls 100 $1.00 Bats 20 $5.00 2006 160 $0.50 22 $22.50

Calculating the Price Level The average level of prices is called the price level. One measure of the price level is the GDP deflator, which is an average of the prices of the goods and services in GDP in the current year expressed as a percentage of the base-year prices. The GDP deflator is calculated in the table on the next slide.

Nominal GDP and real GDP are calculated in the way that you’ve just seen. GDP Deflator = (Nominal GDP ÷ Real GDP)  100. In 2005, the GDP deflator is ($200 ÷ $200)  100 = 100. In 2006, the GDP deflator is ($575 ÷ $250)  100 = 230. Year Nominal GDP Real GDP GDP deflator 2005 $200 100 2006 $575 $250 230

Deflating the GDP Balloon Nominal GDP increases because production—real GDP– increases.

Nominal GDP also increases because prices rise.

We use the GDP deflator to let the inflation air out of the nominal GDP balloon and reveal real GDP.

The Uses and Limitations of Real GDP
We use real GDP to calculate the economic growth rate. The economic growth rate is the percentage change in the quantity of goods and services produced from one year to the next. We measure economic growth so we can make Economic welfare comparisons across time International comparisons across countries Business cycle forecasts

Economic Welfare Comparisons Over Time Economic welfare measures the nation’s overall state of economic well-being. Real GDP is not a perfect measure of economic welfare for seven reasons: 1. Inflation rate tends to be overestimated because quality improvements are neglected, so real GDP is underestimated. 2. Real GDP does not include household production— productive activities done in and around the house by members of the household. Omissions from GDP. A discussion of omissions from GDP can arouse students’ interest. For example, you might point out that if one of your students mows her/his own lawn, the value of the student’s production doesn’t show up in GDP. But if you hire the student to mow your lawn (and if your student reports the income earned correctly to the IRS), the value of the student’s production does show up in GDP. Why don’t we measure all lawn mowing as part of GDP? Some reasons are cost of collecting data and the degree of intrusiveness we’d be willing to tolerate. But note how little we spend on collecting the GDP data and how relatively inexpensive it would be to add some questions about domestic production to either the Current Population Survey or the Family Expenditure Survey. The inclusion of the imputed rental of owner-occupied houses, but not owner-used cars and other durables, is a good example. You might like to explain how the omission of illegal goods and services also leads to some misleading comparisons. For instance, the day before prohibition ended, the production of (illegal) beer was not counted as part of GDP. But the day after prohibition ended, the production of (now legal) beer counted. Ask your students to suggest two good reasons why illegal goods and services are omitted. First, the data are hard (but not impossible) to obtain. Second, there may be the moral position that illegal activities should not be included in GDP. This latter observation can lead to an interesting discussion. Ask the students if they think that the production of, say, marijuana should be included in GDP. Some, maybe even many, of them will see no problem with this. Then ask about the production of murder-for-hire. The response, we hope, will be significantly different. Does such a good have any value?

3. Real GDP, as measured, omits the underground economy, which is illegal economic activity or legal economic activity that goes unreported for tax avoidance reasons. 4. Health and life expectancy are not directly included in real GDP. 5. Leisure time, a valuable component of an individual’s welfare, is not included in real GDP. 6. Environmental damage is not deducted from real GDP. 7. Political freedom and social justice are not included in real GDP.

Economic Welfare Comparisons Across Countries Real GDP is used to compare economic welfare in one country with that in another. Two special problems arise in making these comparisons. Real GDP of one country must be converted into the same currency units as the real GDP of the other country, so an exchange rate must be used. The same prices should be used to value the goods and services in the countries being compared, but often are not.

Using the exchange rate to compare GDP in one country with GDP in another country is problematic because prices of particular products in one country may be much less or much more than in the other country. For example, using the market exchange rate to value Chinese GDP in dollars leads to an estimate that in 2006, U.S. real GDP per person was 28 times Chinese real GDP per person. International comparisons and PPP prices. Students sometimes see estimates of GDP per person in developing nations. Most such estimates are extremely low, and students often ask how people can live on such low incomes. Point out that the estimate is biased downward in two ways. First, in poor nations, more transactions do not go through a market than in rich nations. For example, transportation services in developing nations include a lot of walking, which is not counted as part of GDP. In richer nations, people ride a bus or subway and pay a fare, which is counted as part of GDP. Second, many locally produced and consumed goods and services have extremely low prices in poor nations. For example, a haircut that costs $20 in New York might cost $1 in Calcutta. (You might get a better haircut in New York, but probably not one that is 20 times better!) Converting Indian GDP into U.S. dollars at the market exchange rate leaves this bias in the data. Using purchasing power parity prices to convert India’s GDP into U.S. dollars avoids this bias.

Figure 5.4 illustrates the problem. Using the market exchange rate and domestic prices leads to an estimate that China is very poor. U.S. GDP per person is 28 times that in China.

Using purchasing power parity prices leads to an estimate that U.S. GDP per person is (only) 12 times that in China. The difference in the two sets of numbers is astonishingly large and makes a dramatic difference to how we view the balance of economic power over the next 25 years. At current growth rates and market exchange rates, by 2020, China will have a GDP around a quarter that of the United States. At current growth rates and PPP exchange rates, China’s real GDP will exceed that of the United States before 2020. Per person, China in 2020 will still have a long way to go to catch the United States. But China’s economy will be the world’s largest.

Business Cycle Forecasts Real GDP is used to measure business cycle fluctuations. These fluctuations are probably accurately timed, but the changes in real GDP probably overstate the changes in total production and people’s welfare caused by business cycles.

THE END

5 Measuring GDP and Economic Growth

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