宏观经济学的数据.ppt

1,CHAPTER 2 The Data of Macroeconomics,MANKIWS MACROECONOMICS MODULES,A PowerPointTutorial To Accompany MACROECONOMICS, 6th. ed. N. Gregory Mankiw,2,GDP, CPI, and Uemployment,Gross Domestic Product (GDP) is the dollar value of all final goods and services produced within an economy in a given period of time. The consumer price index (CPI) measures the level of prices. The unemployment rate tells us the fraction of workers who are unemployed.,3,For the economy as a whole, income must equal expenditure. GDP measures the flow of dollars in the economy.,Income, Expenditure, And the Circular Flow,4,Rules for Computing GDP,1) To compute the total value of different goods and services, the national income accounts use market prices. Thus, if,GDP = (Price of apples Quantity of apples) + (Price of oranges Quantity of oranges) = ($0.50 4) + ($1.00 3) GDP = $5.00,2) Used goods are not included in the calculation of GDP. 3) The treatment of inventories depends on if the goods are stored or if they spoil. If the goods are stored, their value is included in GDP. If they spoil, GDP remains unchanged. When the goods are finally sold out of inventory, they are considered used goods (and are not counted).,5,More Rules for Computing GDP,4) Intermediate goods are not counted in GDP only the value of final goods. Reason: the value of intermediate goods is already included in the market price. Value added of a firm equals the value of the firms output less the value of the intermediate goods the firm purchases. 5) Some goods are not sold in the marketplace and therefore dont have market prices. We must use their imputed value as an estimate of their value. For example, home ownership and government services.,6,Real vs. Nominal GDP,The value of final goods and services measured at current prices is called nominal GDP. It can change over time, either because there is a change in the amount (real value) of goods and services or a change in the prices of those goods and services. Hence, nominal GDP Y = P y, where P is the price level and y is real outputand remember we use output and GDP interchangeably. Real GDP or, y = YP is the value of goods and services measured using a constant set of prices.,This distinction between real and nominal can also be applied to other monetary values, like wages. Nominal (or money) wages can be denoted by W and decomposed into a real value (w) and a price variable (P). Hence, W = nominal wage = P w w = real wage = w/P,This conversion from nominal to real units allows us to eliminate the problems created by having a measuring stick (dollar value) that essentially changes length over time, as the price level changes.,7,Lets see how real GDP is computed in our apple and orange economy.,For example, if we wanted to compare output in 2006 and output in 2007, we would obtain base-year prices, such as 2006 prices. Real GDP in 2006 would be: (2006 Price of Apples 2006 Quantity of Apples) + (2006 Price of Oranges 2006 Quantity of Oranges). Real GDP in 2007 would be: (2006 Price of Apples 2007 Quantity of Apples) + (2006 Price of Oranges 2007 Quantity of Oranges). Real GDP in 2008 would be: (2006 Price of Apples 2008 Quantity of Apples) + (2006 Price of Oranges 2008 Quantity of Oranges). Note that 2006 prices are used to compute real GDP for all three years. Because prices are held constant from year to year, real GDP varies only when the quantities vary.,8,GDP Deflator,Nominal GDP measures the current dollar value of the output of the economy. Real GDP measures output valued at constant prices. The GDP deflator, also called the implicit price deflator for GDP, measures the price of output relative to its price in the base year. It reflects whats happening to the overall level of prices in the economy.,THE IMPLICIT PRICE DEFLATOR FOR GDP,9,Chain-Weighted Measures of GDP,In some cases, it is misleading to use base-year prices that prevailed 10 or 20 years ago (i.e., computers and college). In 1995, the Bureau of Economic Analysis decided to use chain-weighted measures of real GDP. The base year changes continuously over time. This new chain-weighted measure is better than the more traditional measure because it ensures that prices will not be too out of date.,Average prices in 2006 and 2007 are used to measure real growth from 2006 to 2007. Average prices in 2007 and 2008 are used to measure real growth from 2007 to 2008, and so on. These growth rates are united to form a chain that is used to compare output between any two dates.,10,Components of Expenditure,Y = C + I + G + NX,This is the called the national income accounts identity.,11,Other Measures of Income,To see how the alternative measures of income relate to one another, we start with GDP and add or subtract various quantities. To obtain gross national product (GNP), we add receipts of factor income (wages, profit, and rent) from the rest of the world and subtract payments of factor income to the rest of the world. GNP = GDP + Factor Payments from Abroad - Factor Payments to Abroad Whereas GDP measures the total income produced domestically, GNP measures the total income earned by nationals (residents of a nation). To obtain net national product (NNP), we subtract the depreciation of capitalthe amount of the economys stock of plants, equipment, and residential structures that wears out during the year: NNP = GNP Depreciation,National Income = NNP Indirect Business Taxes.,12,National income measures how much everyone in the economy has earned.The national income accounts divide national income into five components, Compensation of employees.The wages and fringe benefits earned by workers. Proprietors income.The income of noncorporate businesses, such as small farms, mom-and-pop stores, and law partnerships. Rental income .The income that landlords receive, including the imputed rent that homeowners “pay to themselves, less expenses, such as depreciation. Corporate profits .The income of corporations after payments to their workers and creditors. Net interest .The interest domestic businesses pay minus the interest they receive, plus interest earned from foreigners.,13,Personal Income = National Income 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.,14,Computing the CPI,The Consumer Price Index (CPI) turns the prices of many goods and services into a single index measuring the overall level of prices. The Bureau of Labor Statistics weighs different items by computing the price of a basket of goods and services produced by a typical customer. The CPI is the price of this basket of goods relative to the price of the same basket in some base year.,15,Lets see how the CPI would be computed in our apple and orange economy.,16,CPI Versus the GDP Deflator,The GDP deflator measures the prices of all goods produced, whereas the CPI measures prices of only the goods and services bought by consumers. Thus, an increase in the price of goods bought only by firms or the government will show up in the GDP deflator, but not in the CPI. Also, another difference is that the GDP deflator includes only those goods and services produced domestically. Imported goods are not a part of GDP and therefore dont show up in the GDP deflator. The final difference is the way the two aggregate the prices in the economy. The CPI assigns fixed weights to the prices of different goods, whereas the GDP deflator assigns changing weights.,17,Measuring Unemployment,The labor force is defined as the sum of the employed and unemployed, and the unemployment rate is defined as the percentage of the labor force that is unemployed. The labor-force participation rate is the percentage of the adult population who are in the labor force.,18,The Bureau of Labor Statistics (BLS) computes these statistics for the overall population and for groups within the population: men and women, whites and blacks, teenagers, and prime-age workers. Labor Force = 147.4 million Unemployment rate = 5.5% Labor-Force Participation Rate = 66.0%,The Bureau Labor Statistics Labor Force = 147.4 million Unemployment rate = 5.5% Labor Force Participation Rate = 66.0%,19,The Household Survey,The BLS conducts two surveys of labor market, and therefore produces two measures of total employment. The establishment survey estimates the number of workers firms have on their payrolls. The household survey estimates the number of people who say they are working. Two measures of employment are not necessarily identical, although positively correlated. The reason? The surveys measure different things and the surveys in general, are imperfect. Some economists believe that the establishment survey is more accurate because it has a larger sample size. Bottom line: all economic statistics are imperfect!,The Establishment Survey &,20,National income accounts identity Consumption Investment Government purchases Net exports Labor force Labor-force participation rate,Gross domestic product (GDP) Consumer Price Index (CPI) Unemployment rate National income accounting Stocks and flows Value added Imputed value Nominal versus real GDP GDP deflator,Key Concepts of Ch. 2,21,2. Value added by each person is the value of the good produced minus the amount the person paid for the materials necessary to make the good. Therefore, the value added by the farmer is $1.00 ($1 0 = $1). The value added by the miller is $2: she sells the flour to the baker for $3 but paid $1 for the flour. The value added by the baker is $3: she sells the bread to the engineer for $6 but paid the miller $3 for the flour. GDP is the total value added, or $1 + $2 + $3 = $6. Note that GDP equals the value of the final good (the bread).,22,3. When a woman marries her butler, GDP falls by the amount of the butlers salary. This happens because measured total income, and therefore measured GDP, falls by the amount of the butlers loss in salary. If GDP truly measured the value of all goods and services, then the marriage would not affect GDP since the total amount of economic activity is unchanged. Actual GDP, however, is an imperfect measure of economic activity because the value of some goods and services is left out. Once the butlers work becomes part of his household chores, his services are no longer counted in GDP. As this example illustrates, GDP does not include the value of any output produced in the home. Similarly, GDP does not include other goods and services, such as the imputed rent on durable goods (e.g., cars and refrigerators) and any illegal trade.,23,4. a. government purchases b. investment c. net exports d. consumption e. investment,24,8. a. Real GDP falls because Disney does not produce any services while it is closed.This corresponds to a decrease in economic well-being because the income of workers and shareholders of Disney falls (the income side of the national accounts),and peoples consumption of Disney falls (the expenditure side of the national accounts). b. Real GDP rises because the original capital and labor in farm production now produce more wheat. This corresponds to an increase in the economic well-being of society, since people can now consume more wheat. (If people do not want to consume more wheat, then farmers and farmland can be shifted to producing other goods that society values.) c. Real GDP falls because with fewer workers on the job, firms produce less. This accurately reflects a fall in economic well-being. d. Real GDP falls because the firms that lay off workers produce less. This decreases economic well-being because workers incomes fall (the income side), and there are fewer goods for people to buy (the expenditure side).,25,e. Real GDP is likely to fall, as firms shift toward production methods that produce fewer goods but emit less pollution. Economic well-being, however, may rise. The economy now produces less measured output but more clean air; clean air is not traded in markets and, thus, does not show up in measured GDP, but is nevertheless a good that people value. f. Real GDP rises because the high-school students go from an activity in which they are not producing market goods and services to one in which they are. Economic well-being, however, may decrease. In ideal national accounts, attending school would show up as investment b