Chapter 4: Measuring GDP and Economic Growth

1. Definition of GDP 2. Use circular flow model to explain how GDP can

be measured from income or expenditure side.3. Measurement of GDP and its major components.4. GDP as a measure of economic growth.5. Limitations of GDP as a measure of economic

growth or the standard of living.

Definition of GDP• GDP (Gross Domestic Product) is the market value of all

final goods and services produced in a country in a given time period.

– Market value• goods & services are valued at their market prices.• GDP rises if prices rise (more on this later)

– Final goods and services• Bought by final user• Intermediate goods are produced by one firm, bought by

another, and used as a component of a final good or service.• Exclude sale/purchase of intermediate goods to avoid double

counting.

• Produced within a country– Any domestic production, regardless of who owns the

resources• In a given time period– Production during a specific year (sales of used items

excluded, except value of service in sale)– Inventory adjustments account for goods produced in

one year but sold in another• if inventories rise by $10 million during 2010, $10 million is

added to sales of final goods & services since it reflects goods produced but not sold during 2010.

• If inventories fall by $10 million during 2010, $10 million is subtracted from sales of final goods & services because $10 million was sold during 2010 that was produced prior to 2010.

Definition of GDP

• Households sell factors of production the firms in factor markets– Factors of production: land, labor, capital• Wages for labor• Interest for loans used to purchase capital• Rent for the use of land• Profit to owners of capital

• Total income paid to households=Y

GDP and Circular Flow

Expenditure Components of GDP• Consumption (C)– total payment for consumer goods and services

• Investment (I)– purchase of new plant, equipment, and buildings – additions to inventories

• Government spending (G): – government purchases of goods and services from firms– excludes “transfer payments” such as Social Security,

Unemployment Insurance• Net exports (X-M)– (exports-imports)– Imports subtracted because counted as part of C,I,G and

are not part of domestic production.

Y=total income; C=consumption; I=investment; G=government purchases; X-M=exports-imports=net exports

GDP: Income & Expenditure Approach

• GDP can be measured by income (blue flows) or expenditure (red) side

• Circular flow demonstrates thatY = C + I + G + (X-M)

Gross vs Net Domestic Product

• GDP is before subtracting depreciation (capital consumption allowance)

• NDP =GDP- CCA– NDP is “net of” depreciation.

• Capital in t = Capital in (t-1) + Gross Investment –CCA = Capital in (t-1) + Net Investment

where Net investment = Gross investment – CCA

If capital is $8 trillion at the end of 2008 and $7.7 trillion at the end of 2009

1 2 3 4

0% 0%0%0%

10

1. Gross investment is $.3 trillion in 2009

2. Gross investment is -$.3 trillion in 2009

3. Net investment is $.3 in 2009

4. Net investment is -$.3 trillion in 2009

GDP: The Expenditure Side

GDP: The Income Side• Income includes

1. Compensation of employees 2. Rental income 3. Net interest 4. Corporate profits 5. Proprietors’ income

• Two adjustments to income required: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

GDP: The Income Side

GDP: Adjusting for changes in prices

Nominal GDP • the value of goods and services produced during a given

year valued at the prices that prevailed in that same year.• Nominal GDP is a more precise name for GDP.

Real GDP • the value of final goods and services produced in a given

year when valued at the prices of a reference base year.

2000 2010

Product Quantity Price Quantity Price

computers 100 $500 120 $600

refrigerators 50 $1000 100 $1500

Nominal GDP

Real GDP (2000 base year)

Real GDP (2010 base year)

GDP-deflator (2000 base year)

GDP-deflator (2010 base year)

GDP Deflator

• GDP deflator– Provides a comparison of current and base year

prices

100GDP Real

GDP Nominaldeflator -GDP

t

t xt

Real GDP and the Price LevelItem Quant. Price

2002

Balls 100 $1.00

Bats 20 $5.00

2003

Balls 160 $1.00

Bats 22 $10.00

• 2002 NGDP ________• 2003 NGDP ________

• Base year of 2002• 2002 RDGP ________• 2003 RGDP ________

• For your answers to the next several slides, give your estimates of GDP to the nearest dollar, do not include decimals, and do not include $ signs.

Lucas Wedge• dollar value of the accumulated gap between what real GDP

per person would have been if the 1960s growth rate had persisted and what real GDP per person turned out to be.

Temporary fluctuations in GDP:The Business Cycle

• 4 stages to a business cycle– Peak– Recession– Trough– Expansion

Comparing Standard of Living Across Countries

• Use per capita real GDP• Must make two adjustments– Convert into common currency– Goods and services must be valued at same prices

• Using the exchange rate to convert can be problematic because prices of some products may differ after conversion

• Purchasing Power Parity exchange rate is the exchange rate that would make the prices of goods and services equal across countries.

• Using actual exchange rate instead of PPP exchange rate causes underestimate of standard of living in less developed countries.

•With actual exchange rates, China RGDP per capita is 5% of that in U.S. •With PPP exchange rates, China RGDP per capita is 12.5% of that in U.S.

Real GDP per capita across the world

Source: http://www.imf.org/external/datamapper/index.php

Limitations of GDP as measure of standard of living

• Household production• Underground economic activity• Health and life expectancy• Leisure time• Environmental quality• Political freedom and social justice