The Data of Macroeconomics Adapted for EC 204 by Prof. Bob Murphy: The Data of Macroeconomics Adapted for EC 204 by Prof. Bob Murphy 2
In this chapter, you will learn…: In this chapter, you will learn… …the meaning and measurement of the most important macroeconomic statistics:
Gross Domestic Product (GDP)
The Consumer Price Index (CPI)
The unemployment rate
Gross Domestic Product: Expenditure and Income: Gross Domestic Product: Expenditure and Income Two definitions:
Total expenditure on domestically-produced final goods and services.
Total income earned by domestically-located factors of production.
The Circular Flow: The Circular Flow Households Firms
Gross Domestic Product: Expenditure and Income: Gross Domestic Product: Expenditure and Income One caveat:
Measurement of income and expenditure is imperfect.
Difference in GDP and Gross Domestic Income GDI) is called the “Statistical Discrepancy.”
Value added: Value added definition:
A firm’s value added is the value of its output minus the value of the intermediate goods the firm used to produce that output.
Exercise: (Problem 2, p. 40): Exercise: (Problem 2, p. 40) A farmer grows a bushel of wheat and sells it to a miller for $1.00.
The miller turns the wheat into flour and sells it to a baker for $3.00.
The baker uses the flour to make a loaf of bread and sells it to an engineer for $6.00.
The engineer eats the bread.
Compute & compare value added at each stage of production and GDP
Final goods, value added, and GDP: Final goods, value added, and GDP GDP = value of final goods produced
= sum of value added at all stages of production.
The value of the final goods already includes the value of the intermediate goods, so including intermediate and final goods in GDP would be double-counting.
The expenditure components of GDP: The expenditure components of GDP consumption
investment
government spending
net exports
Consumption (C): Consumption (C) durable goods last a long time ex: cars, home appliances
nondurable goods last a short time ex: food, clothing
services work done for consumers ex: dry cleaning, air travel. definition: The value of all goods and services bought by households. Includes:
U.S. consumption, 2005: U.S. consumption, 2005 70.0% $8,745.7
Investment (I): Investment (I) Definition 1: Spending on [the factor of production] capital.
Definition 2: Spending on goods bought for future use
Includes:
business fixed investment Spending on plant and equipment that firms will use to produce other goods & services.
residential fixed investment Spending on housing units by consumers and landlords.
inventory investment The change in the value of all firms’ inventories.
U.S. investment, 2005: U.S. investment, 2005 16.9% $2,105.0
Investment vs. Capital: Investment vs. Capital Note: Investment is spending on new capital.
Example (assumes no depreciation):
1/1/2006: economy has $500b worth of capital
during 2006: investment = $60b
1/1/2007: economy will have $560b worth of capital
Stocks vs. Flows: Stocks vs. Flows A flow is a quantity measured per unit of time.
E.g., “U.S. investment was $2.5 trillion during 2006.” A stock is a quantity measured at a point in time.
E.g., “The U.S. capital stock was $26 trillion on January 1, 2006.”
Stocks vs. Flows - examples: Stocks vs. Flows - examples the govt budget deficit the govt debt # of new college graduates this year # of people with college degrees a person’s annual saving a person’s wealth flow stock
Now you try: : Now you try: Stock or flow?
the balance on your credit card statement
how much you study economics outside of class
the size of your compact disc collection
the inflation rate
the unemployment rate
Government spending (G): Government spending (G) G includes all government spending on goods and services..
G excludes transfer payments (e.g., unemployment insurance payments), because they do not represent spending on goods and services.
U.S. government spending, 2005: U.S. government spending, 2005 Federal 18.9% $2,362.9 Govt spending State & local Defense Non-defense % of GDP $ billions
Net exports: NX = EX – IM: Net exports: NX = EX – IM def: The value of total exports (EX) minus the value of total imports (IM).
An important identity: An important identity Y = C + I + G + NX
A question for you:: A question for you: Suppose a firm
produces $10 million worth of final goods
but only sells $9 million worth.
Does this violate the expenditure = output identity?
Why output = expenditure: Why output = expenditure Unsold output goes into inventory, and is counted as “inventory investment”…
…whether or not the inventory buildup was intentional.
In effect, we are assuming that firms purchase their unsold output.
GDP: An important and versatile concept: GDP: An important and versatile concept We have now seen that GDP measures
total income
total output
total expenditure
the sum of value-added at all stages in the production of final goods
GNP vs. GDP: GNP vs. GDP Gross National Product (GNP): Total income earned by the nation’s factors of production, regardless of where located.
Gross Domestic Product (GDP): Total income earned by domestically-located factors of production, regardless of nationality.
(GNP – GDP) = (factor payments from abroad) – (factor payments to abroad)
Discussion question:: Discussion question: In your country, which would you want to be bigger, GDP, or GNP?
Why?
(GNP – GDP) as a percentage of GDP selected countries, 2002: (GNP – GDP) as a percentage of GDP selected countries, 2002
Other Measures of Income: Other Measures of Income National Income = GNP - Depreciation
National Income = Compensation of Employees + Proprietors’ Income + Rental Income + Corporate Profits + Net Interest + Indirect Business Taxes
Note: Supplement 2-7 describes recent change in definition of National Income to include Indirect Business Taxes.
Components of National Income: Components of National Income
Other Measures of Income: Other Measures of Income Personal Income = National Income - Indirect Business Taxes - Corporate Profits - Social Insurance Contributions - Net Interest + Dividends + Government Transfers to Individuals + Personal Interest Income
Disposable Personal Income = Personal Income - Personal Tax and Nontax Payments
Disposable Personal Income is what households and noncorporate businesses have to spend (or save).
Real vs. nominal GDP: Real vs. nominal GDP GDP is the value of all final goods and services produced.
nominal GDP measures these values using current prices.
real GDP measure these values using the prices of a base year.
Real vs. nominal GDP: Real vs. nominal GDP
Practice problem, part 1: Practice problem, part 1 Compute nominal GDP in each year.
Compute real GDP in each year using 2006 as the base year.
Answers to practice problem, part 1: Answers to practice problem, part 1 nominal GDP multiply Ps & Qs from same year 2006: $46,200 = $30 900 + $100 192 2007: $51,400 2008: $58,300
real GDP multiply each year’s Qs by 2006 Ps 2006: $46,200 2007: $50,000 2008: $52,000 = $30 1050 + $100 205
Real GDP controls for inflation: Real GDP controls for inflation Changes in nominal GDP can be due to:
changes in prices.
changes in quantities of output produced.
Changes in real GDP can only be due to changes in quantities,
because real GDP is constructed using constant base-year prices.
U.S. Nominal and Real GDP, 1950–2006: U.S. Nominal and Real GDP, 1950–2006 Nominal GDP Real GDP (in 2000 dollars)
GDP Deflator: GDP Deflator The inflation rate is the percentage increase in the overall level of prices.
One measure of the price level is the GDP deflator, defined as
Practice problem, part 2: Practice problem, part 2 Use your previous answers to compute the GDP deflator in each year.
Use GDP deflator to compute the inflation rate from 2006 to 2007, and from 2007 to 2008.
Answers to practice problem, part 2: Answers to practice problem, part 2
Understanding the GDP deflator: Understanding the GDP deflator Example with 3 goods
For good i = 1, 2, 3
Pit = the market price of good i in month t
Qit = the quantity of good i produced in month t
NGDPt = Nominal GDP in month t
RGDPt = Real GDP in month t
Understanding the GDP deflator: Understanding the GDP deflator The GDP deflator is a weighted average of prices.
The weight on each price reflects that good’s relative importance in GDP.
Note that the weights change over time.
Two arithmetic tricks for working with percentage changes: Two arithmetic tricks for working with percentage changes EX: If your hourly wage rises 5% and you work 7% more hours, then your wage income rises approximately 12%. 1. For any variables X and Y,
percentage change in (X Y ) percentage change in X + percentage change in Y
Two arithmetic tricks for working with percentage changes: Two arithmetic tricks for working with percentage changes EX: GDP deflator = 100 NGDP/RGDP.
If NGDP rises 9% and RGDP rises 4%, then the inflation rate is approximately 5%. 2. percentage change in (X/Y ) percentage change in X percentage change in Y
Measuring Economic Growth: Measuring Economic Growth
Measuring Economic Growth: Measuring Economic Growth
Measuring Economic Growth: Measuring Economic Growth A problem arises when using fixed base-year weights: Growth will vary depending on base year chosen.
Rapidly growing sectors with declining relative prices will be weighted “too much” as base year becomes further and further in the past. Opposite for slowly growing sectors.
Chain-Weighted Real GDP: Chain-Weighted Real GDP Over time, relative prices change, so the base year should be updated periodically--which BEA used to do.
In essence, chain-weighted real GDP updates the base year every year, so it is more accurate than fixed base-year GDP.
Official measure of GDP now produced by BEA.
See Supplement 2-4.
Chain-Weighted Real GDP: Chain-Weighted Real GDP Step 1: Rewrite as:
Chain-Weighted Real GDP: Chain-Weighted Real GDP Step 2: Rewrite as:
Chain-Weighted Real GDP: Chain-Weighted Real GDP Step 3: To get level of real GDP, use nominal GDP for a given year and apply growth rate: Real GDP is measured here in year t-4 dollars.
When is the Economy in a Recession?: When is the Economy in a Recession? Rule of Thumb: Two quarters of decline in Real GDP
National Bureau of Economic Research uses more nuanced approach (see Supplement 1-3):
Monthly Indicators rather than Quarterly.
“A significant decline in activity spread across the economy, lasting more than a few months, visible in industrial production, employment, real income, and wholesale-retail trade.”
Consumer Price Index (CPI): Consumer Price Index (CPI) A measure of the overall level of prices
Published by the Bureau of Labor Statistics (BLS)
Uses:
tracks changes in the typical household’s cost of living
adjusts many contracts for inflation (“COLAs”)
allows comparisons of dollar amounts over time
How the BLS constructs the CPI: How the BLS constructs the CPI 1. Survey consumers to determine composition of the typical consumer’s “basket” of goods.
2. Every month, collect data on prices of all items in the basket; compute cost of basket
3. CPI in any month equals
Exercise: Compute the CPI: Exercise: Compute the CPI Basket contains 20 pizzas and 10 compact discs. prices:
pizza CDs
2002 $10 $15
2003 $11 $15
2004 $12 $16
2005 $13 $15 For each year, compute
the cost of the basket
the CPI (use 2002 as the base year)
the inflation rate from the preceding year
Answers:: Cost of Inflation
basket CPI rate
2002 $350 100.0 n.a.
2003 370 105.7 5.7%
2004 400 114.3 8.1%
2005 410 117.1 2.5% Answers:
The composition of the CPI’s “basket”: The composition of the CPI’s “basket”
Understanding the CPI: Understanding the CPI Example with n goods
For good i = 1, 2, 3, …., n
QiB = the amount of good i in the CPI’s basket
Pit = the price of good i in month t
Et = the cost of the CPI basket in month t
Eb = the cost of the basket in the base period
Understanding the CPI: Understanding the CPI The CPI is a weighted average of prices.
The weight on each price reflects that good’s relative importance in the CPI’s basket.
Note that the weights remain fixed over time.
Understanding the CPI: Understanding the CPI
Understanding the CPI: Understanding the CPI where the weights are given by:
Understanding the CPI: Understanding the CPI The CPI is a weighted average of prices relative to their value in the base period.
The weight on each “price relative” reflects that good’s relative importance in the CPI’s basket.
Note that the weights remain fixed over time.
Reasons why the CPI may overstate inflation: Reasons why the CPI may overstate inflation Substitution bias: The CPI uses fixed weights, so it cannot reflect consumers’ ability to substitute toward goods whose relative prices have fallen.
Introduction of new goods: The introduction of new goods makes consumers better off and, in effect, increases the real value of the dollar. But it does not reduce the CPI, because the CPI uses fixed weights.
Unmeasured changes in quality: Quality improvements increase the value of the dollar, but are often not fully measured. Has to do with how prices of goods are measured.
The size of the CPI’s bias: The size of the CPI’s bias In 1995, a Senate-appointed panel of experts estimated that the CPI overstates inflation by about 1.1% per year.
So the BLS made adjustments to reduce the bias.
Now, the CPI’s bias is probably under 1% per year.
See Supplements 2-10 and 2-11.
Discussion questions:: Discussion questions: If your grandmother receives Social Security, how is she affected by the CPI’s bias?
Where does the government get the money to pay COLAs to Social Security recipients?
If you pay income and Social Security taxes, how does the CPI’s bias affect you?
Is the government giving your grandmother too much of a COLA?
How does your grandmother’s “basket” differ from the CPI’s?
CPI vs. GDP Deflator: CPI vs. GDP Deflator Prices of Capital Goods
included in GDP deflator (if produced domestically)
excluded from CPI
Prices of Imported Consumer Goods
included in CPI
excluded from GDP deflator
The Basket of Goods
CPI: fixed
GDP deflator: changes every year
Two measures of inflation in the U.S.: Two measures of inflation in the U.S. Percentage change from 12 months earlier
Categories of the population: Categories of the population employed working at a paid job
unemployed not employed but looking for a job
labor force the amount of labor available for producing goods and services; all employed plus unemployed persons
not in the labor force not employed, not looking for work
Two important labor force concepts: Two important labor force concepts unemployment rate percentage of the labor force that is unemployed (see Supplement 2-12 for alternative measures of the unemployment rate)
labor force participation rate the fraction of the adult population that “participates” in the labor force
Exercise: Compute labor force statistics: Exercise: Compute labor force statistics U.S. adult population by group, June 2006
Number employed = 144.4 million
Number unemployed = 7.0 million
Adult population = 228.8 million Use the above data to calculate
the labor force
the number of people not in the labor force
the labor force participation rate
the unemployment rate
Answers:: Answers: data: E = 144.4, U = 7.0, POP = 228.8
labor force L = E +U = 144.4 + 7 = 151.4
not in labor force NILF = POP – L = 228.8 – 151.4 = 77.4
unemployment rate U/L x 100% = (7/151.4) x 100% = 4.6%
labor force participation rate L/POP x 100% = (151.4/228.8) x 100% = 66.2%
Exercise: Compute percentage changes in labor force statistics: Exercise: Compute percentage changes in labor force statistics Suppose
population increases by 1%
labor force increases by 3%
number of unemployed persons increases by 2%
Compute the percentage changes in
the labor force participation rate:
the unemployment rate: 2% 1%
The establishment survey: The establishment survey The BLS obtains a second measure of employment by surveying businesses, asking how many workers are on their payrolls.
Neither measure is perfect, and they occasionally diverge due to:
treatment of self-employed persons
new firms not counted in establishment survey
technical issues involving population inferences from sample data
Two measures of employment growth: Household Survey and the Establishment Survey: Two measures of employment growth: Household Survey and the Establishment Survey Percentage change from 12 months earlier
Chapter Summary: Chapter Summary 1. Gross Domestic Product (GDP) measures both total income and total expenditure on the economy’s output of goods & services.
2. Nominal GDP values output at current prices; real GDP values output at constant prices. Changes in output affect both measures, but changes in prices only affect nominal GDP.
3. GDP is the sum of consumption, investment, government purchases, and net exports. slide 73 CHAPTER 2 The Data of Macroeconomics
Chapter Summary: Chapter Summary 4. The overall level of prices can be measured by either
the Consumer Price Index (CPI), the price of a fixed basket of goods purchased by the typical consumer, or
the GDP deflator, the ratio of nominal to real GDP
5. The unemployment rate is the fraction of the labor force that is not employed. slide 74 CHAPTER 2 The Data of Macroeconomics