宏观经济学---曼昆02

CHAPTER 2
The Data of Macroeconomics
Gross Domestic Product
GDP is often considered the best measure of how well the economy is performing; - summarize in a single number the dollar value of economic activity in a given period of time.
Total income earned by domestically-located factors of production.
Expenditure equals income because every dollar spent by a buyer becomes income to the seller.
CHAPTER 2
The Data of Macroeconomics
Stocks vs. Flows - examples
stock a person’s wealth # of people with college degrees the govt debt flow
a person’s annual saving
CHAPTER 2
The Data of Macroeconomics
The Circular Flow
Income ($)
Labor
Households
Firms
Goods Expenditure ($)
CHAPTER 2
The Data of Macroeconomics
Measurement of GDP
CHAPTER 2
The Data of Macroeconomics
Used goods
GDP measures the value of currently produced goods and services. Thus, the sale of used goods reflects the transfer of an asset, not an addition to the economy’s income; Thus, it is not included as part of GDP.
CHAPTER 2
The Data of Macroeconomics
Exercise:
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.
GDP measures the flow of dollars in the economy. Total income from the production of bread:
- top half of the circular flow
Total expenditure on purchases of bread:
CHAPTER 2
The Data of Macroeconomics
Rules for Computing GDP
Adding apples and oranges Used goods Treatment of inventories Intermediate goods and value added Housing services and other imputations
…the meaning and measurement of the most important macroeconomic statistics:
Gross Domestic Product (GDP) The Consumer Price Index (CPI) The unemployment rate Economists use these statistics to study the economy; policymakers use them to monitor development and formulate policies.
CHAPTER 2
The Data of Macroeconomics
Gross Domestic Product: Expenditure and Income
Two definitions:
Total expenditure on domestically-produced final goods and services.
CHAPTER 2
The Data of Macroeconomics
National Income Accounting
To understand the meaning of GDP more fully, we turn to national income accounting, the accounting system used to measure GDP and many related statistics.
CHAPTER 2
The Data of Macroeconomics
Adding apples and oranges
To compute the total value of different goods and services, NIA use market prices because these prices reflect how much people are willing to pay for a good or services. GDP = (Price of Apples * Quantity of Apples) + (Price of Oranges * Quantity of Oranges)
Chapoeconomics
ZHAO, Qiwei
Economics and Management School, Wuhan University
2014 Economics and Management School, Wuhan University
In this chapter, you will learn…
- bottom half of the circular flow
To compute GDP, we can look at either side of the flows.
CHAPTER 2
The Data of Macroeconomics
Stocks vs. Flows
Flow
Stock
Compute & compare value added at each stage of production and GDP
CHAPTER 2
The Data of Macroeconomics
Housing services and other imputations
Some goods and services are not sold in the marketplace and do not have market prices. We must use an estimate of their value (imputed value) Imputations are useful for determining the value of housing or government services. In many cases, imputations are not made in practice. (ex, home-made meals, underground economy) GDP is an imperfect measure of economic activity.
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.”
A flow is a quantity measured per unit of time. E.g., “U.S. investment was $2.5 trillion during 2006.”
# of new college graduates this year the govt budget deficit
CHAPTER 2
The Data of Macroeconomics
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
CHAPTER 2
The Data of Macroeconomics
Treatment of inventories
A bakery hires workers to produce more bread, pays their wages, and then fail to sell the additional bread. What happens to GDP? Case1: The bread spoiled. More wages and less profit. Total expenditure and income do not change. Case2: The bread is put into inventory. The firms are assumed to have “purchased” the bread for inventory. GDP rises. Later, inventory disinvestment occurs, which case is much like the sale of a used good.