1. Measuring a Nation’s Income
based on Gregory Mankiw,
Principles of Economics

2. Outline How to measure national income? Definition of GDP
Satellite GDP Accounts
GDP, GNP, NDP, NNP
Three Methods to measure GDP
Real GDP versus nominal GDP; GDP Deflator
Some data from U.S. and Turkey
GDP per capita and economic well-being
The Indicators Criteria of well-being

3. THE MEASUREMENT OF NATIONAL INCOME
Gross domestic product (GDP) is a measure of the income and expenditures of an economy.
GDP is the total market value of all final goods and services produced within a country in a given period of time.
Note: we are using production, income and expenditures all at once; and we are saying that we use “production” or “expenditures” to measure “income”.
How come?

4. THE ECONOMY’S INCOME AND EXPENDITURE
For an economy as a whole, income must equal expenditure because:
Every transaction has a buyer and a seller.
Every dollar of spending by some buyer is a dollar of income for some seller.
For example, you pay a restaurant owner $100 for a meal; this is your expenditures; but it is the income for the rest owner.
The equality of income and expenditure can be illustrated with the circular-flow diagram.

5. Figure 1 The Circular-Flow Diagram
Firms sell
Households buy
MARKETS
FOR
GOODS AND SERVICES
Revenue
Spending
Goods
and services
sold
Goods and
services
bought
FIRMS
Produce and sell
goods and services
Hire and use factors
of production
Buy and consume
goods and services
Own and sell factors
of production
HOUSEHOLDS
Households sell
Firms buy
MARKETS
FOR
FACTORS OF PRODUCTION
Factors of
production
Labor, land,
and capital
Wages, rent,
and profit
Income
= Flow of inputs
and outputs
= Flow of dollars
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6. THE MEASUREMENT OF GROSS DOMESTIC PRODUCT
For an economy as a whole, income must equal expenditure;
Hence to measure national income we use Gross Domestic Product (GDP).
GDP is the market value of all final goods and services produced within a country in a given period of time.

7. THE MEASUREMENT OF GROSS DOMESTIC PRODUCT
“GDP is the Market Value . . .”
Output is valued at market prices.
“...of all FINAL...”
It records only the value of final goods, not intermediate goods (the value is counted only once).
“. . . Goods and Services “
It includes both tangible goods (food, clothing, cars) and intangible services (haircuts, housecleaning, doctor visits).

8. THE MEASUREMENT OF GROSS DOMESTIC PRODUCT
“. . . Produced . . .”
It includes goods and services currently produced, not transactions involving goods produced in the past.
“ Within a Country . . .”
It measures the value of production within the geographic confines of a country.
“. . . In a Given Period of Time.”
It measures the value of production that takes place within a specific interval of time, usually a year or a quarter (three months).

9. THE MEASUREMENT OF GROSS DOMESTIC PRODUCT
“. . . of ALL Final . . .”
Supposed to be all goods; but a few major categories of produced goods and services left out.
WHAT TYPES OF PRODUCTION GET LEFT OUT OF GDP ACCOUNTS?

10. THE MEASUREMENT OF GROSS DOMESTIC PRODUCT
GDP includes all items produced in the economy and sold legally in markets;
...but it excludes items produced and sold illicitly, such as illegal drugs.
More importantly, GDP excludes most items that are produced and consumed at home and that never enter the marketplace; such as...
Childcare services
Elderly, sick and disabled care services
Home cooked meals
Household maintenance services (washing, cleaning, ironing,...)
etc.

11. Other Measures of National Income: Gross National Product
Gross national product (GNP) is another measure of the income and expenditures of an economy.
GNP is the total market value of all final goods and services produced by the nationals of a country in a given period of time.

12. Other Measures of National Income: Net Domestic Product and Net National Product
“Gross” stands for the fact that GDP/GNP accounts do not take “depreciation” into account.
Depreciation: The wear and tear down of machinery, tools, equipment, infrastructure used up in the production process.
Hence: NDP = GDP – depreciation
NNP = GNP – depreciation
But because depreciation is difficult to estimate accurately, NDP is not used as commonly as GDP.
Nore: environment / natural resources are also used up and environmentalist economists use Satellite Environmental GDP accounts to take the destruction of the environment into consideration.

13. MEASURING GDP: THE EXPENDITURES METHOD
GDP (Y) is the sum of the following:
Consumption (C)
Investment (I)
Government Purchases (G)
Net Exports (NX)
Y = C + I + G + NX

14. THE COMPONENTS OF GDP Consumption (C): Investment (I):
The spending by households on goods and services, with the exception of purchases of new housing.
Investment (I):
The spending on capital equipment, inventories, and structures, including new housing.
Government Purchases (G):
The spending on goods and services by local, state, and federal governments.
Does not include transfer payments because they are not made in exchange for currently produced goods or services.
Net Exports (NX):
Exports minus imports.

15. Table 1 GDP and Its Components
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16. GDP and Its Components (2001)
Government Purchases
18%
Net Exports
-3 %
Investment
16%
Consumption
69%

17. MEASURING GDP: THE INCOME METHOD
GDP (Y) is the sum of the following:
Wage Income (W)
Profit Income (P)
Interest Income (İ)
Government Income: indirect taxes (T)
Y = W + P + İ + T

18. MEASURING GDP: THE VALUE ADDED METHOD
GDP (Y) is the sum of the total value added produced by all firms in the economy:
Value Added of firm i VAi = Revenuesi – Intermediate Costsi
GDP = sum of value added of all firms
Y =∑Ii=1 VAi

19. REAL VERSUS NOMINAL GDP
Nominal GDP values the production of goods and services at current prices.
Real GDP values the production of goods and services at constant prices.
An accurate view of the economy requires adjusting nominal to real GDP by using the GDP deflator.

20. Table 2 Real and Nominal GDP
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21. Table 2 Real and Nominal GDP
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22. Table 2 Real and Nominal GDP
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23. The GDP deflator is calculated as follows:
The GDP deflator is a measure of the price level calculated as the ratio of nominal GDP to real GDP times 100.
It tells us the rise in nominal GDP that is attributable to a rise in prices rather than a rise in the quantities produced.

24. Converting Nominal GDP to Real GDP
The GDP Deflator
Converting Nominal GDP to Real GDP
Nominal GDP is converted to real GDP as follows:

25. Table 2 Real and Nominal GDP
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26. REAL VERSUS NOMINAL GDP

27. Figure 2 Real GDP in the United States
Billions of
1996 Dollars
$10,000
9,000
8,000
7,000
6,000
5,000
4,000
3,000
1970
1975
1980
1985
1990
1995
2000
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28. Real GDP in Turkey (in 1987 fixed prices, YTL)

29. GDP PER CAPITA and ECONOMIC WELL-BEING
GDP per capita = __GDP__
Population
GDP per person tells us the income and expenditure of the average person in the economy;
and is commonly used as a measure of the economic well-being of a society.

30. International Comparisons of Income: Purchasing Power Parity
Qi,m = output vector of all newly produced final goods or services i, in country M
Pi,us = price vector for goods and services i in US prices
As such PPP measure provides the estimated value of Mozambique’s physical output and income weighted by the prices for such goods and services prevailing in the U.S.

31. GDP PER CAPITA and ECONOMIC WELL-BEING
Higher GDP per person generally indicates a higher standard of living;
YET GDP is not a perfect or sufficient measure of the happiness or quality of life and needs to be complimented by other measures.

32. GDP PER CAPITA and ECONOMIC WELL-BEING
Why is GDP not a perfect or sufficient measure of the happiness or quality of life? Because
1. It is just an average number that does not reflect the inequalities in the distribution of income.
2. It is simply an indicator of purchasing power and as such does not necessarily capture a series of quality of life factors that contribute to well-being such as
The value of leisure.
The value of a clean environment.
The value of almost all activity that takes place outside of markets, such as the value of the time parents spend with their children and the value of volunteer work.
The value of the quality of education and health services available
The value of a democratic, participatory and transparent system of governance free of corruption and rights violations;
The value of peace

33. Table 3 GDP, Life Expectancy, and Literacy
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35. The Indicators Criteria of Well-being
Measure of Economic Welfare (MEW)
Genuine Progress Indicator (GPI)
Human Development Index (HDI)
“longevity, knowledge, and a decent standard of living”
Gender-related Development Index (GDI)
Human Poverty Index

36. Figure 1: The human development index gives a more complete picture than income
The HDI for Turkey is 0.775, which gives the country a rank of 84th out of 177 countries with data (Table 1).

37. Summary
Because every transaction has a buyer and a seller, the total expenditure in the economy must equal the total income in the economy.
Gross Domestic Product (GDP) measures an economy’s total expenditure on newly produced goods and services and the total income earned from the production of these goods and services.
GDP is the market value of all final goods and services produced within a country in a given period of time.
GDP is divided among four components of expenditure: consumption, investment, government purchases, and net exports.

38. Summary
Nominal GDP uses current prices to value the economy’s production. Real GDP uses constant base-year prices to value the economy’s production of goods and services.
The GDP deflator—calculated from the ratio of nominal to real GDP—measures the level of prices in the economy.
GDP is a good measure of economic well-being because people prefer higher to lower incomes.
It is not a perfect measure of well-being because some things, such as leisure time and a clean environment, aren’t measured by GDP.