Topic 1 :Topic 1 2304AFE: Macroeconomics Textbook: Macroeconomics By Mankiw, N.G. Edition 6th Chapters: 1 and 2


Learning objectives :Learning objectives This lecture introduces you to the issues macroeconomists study the tools macroeconomists use some important concepts in macroeconomic analysis


Important issues in macroeconomics :Important issues in macroeconomics Why does the cost of living keep rising? Why are people unemployed, even when the economy is booming? Why are there recessions? Can the government do anything to combat recessions? Should it??


Important issues in macroeconomics :Important issues in macroeconomics What is the government budget surplus? How does it affect the economy? Why do Australia and the US have such huge trade deficits? Why are so many countries poor? What policies might help them grow out of poverty?


U.S. Gross Domestic Product in billions of chained 2000 dollars :U.S. Gross Domestic Product in billions of chained 2000 dollars


U.S. Gross Domestic Product in billions of chained 2000 dollars :U.S. Gross Domestic Product in billions of chained 2000 dollars


Why learn macroeconomics? :Why learn macroeconomics? The macroeconomy affects society’s well-being. example: Unemployment and social problems Each one-point increase in the u-rate is associated with: more suicides more homicides more people admitted to state mental institutions more people sent to prison more deaths increases in domestic violence and homelessness


Why learn macroeconomics? :Why learn macroeconomics? The macroeconomy affects your well-being. Unemployment and earnings growth


Why learn macroeconomics? :Why learn macroeconomics? The macroeconomy affects your well-being. Interest rates and mortgage payments For a $150,000 30-year mortgage: $10,959 $913 6.32% $9,888 $824 5.21% 6/17/04


Why learn macroeconomics? :Why learn macroeconomics? The macroeconomy affects politics & current events. Inflation and unemployment in election years The Misery Index The Asian crisis


Economic models :Economic models …are simplied versions of a more complex reality irrelevant details are stripped away Used to show the relationships between economic variables explain the economy’s behavior devise policies to improve economic performance


Example of a model: The supply & demand for new cars :Example of a model: The supply & demand for new cars explains the factors that determine the price of cars and the quantity sold. assumes the market is competitive: each buyer and seller is too small to affect the market price Variables: Q d = quantity of cars that buyers demand Q s = quantity that producers supply P = price of new cars Y = aggregate income Ps = price of steel (an input)


The demand for cars :The demand for cars shows that the quantity of cars consumers demand is related to the price of cars and aggregate income.


Digression: Functional notation :Digression: Functional notation General functional notation shows only that the variables are related:


Digression: Functional notation :Digression: Functional notation General functional notation shows only that the variables are related: A specific functional form shows the precise quantitative relationship:


The market for cars: demand :The market for cars: demand Q Quantity of cars P Price of cars The demand curve shows the relationship between quantity demanded and price, other things equal.


The market for cars: supply :The market for cars: supply


The market for cars: equilibrium :The market for cars: equilibrium


The effects of an increase in income: :The effects of an increase in income: An increase in income increases the quantity of cars consumers demand at each price… …which increases the equilibrium price and quantity.


The effects of a steel price increase: :The effects of a steel price increase: An increase in Ps reduces the quantity of cars producers supply at each price… …which increases the market price and reduces the quantity.


Endogenous vs. exogenous variables: :Endogenous vs. exogenous variables: The values of endogenous variables are determined in the model. The values of exogenous variables are determined outside the model: the model takes their values & behavior as given. In the model of supply & demand for cars,


A Multitude of Models :A Multitude of Models No one model can address all the issues we care about. For example, If we want to know how a fall in aggregate income affects new car prices, we can use the S/D model for new cars. But if we want to know why aggregate income falls, we need a different model.


A Multitude of Models :A Multitude of Models So we will learn different models for studying different issues (e.g. unemployment, inflation, long-run growth). For each new model, you should keep track of its assumptions, which of its variables are endogenous and which are exogenous, the questions it can help us understand, and those it cannot.


Prices: Flexible Versus Sticky :Prices: Flexible Versus Sticky Market clearing: an assumption that prices are flexible and adjust to equate supply and demand. In the short run, many prices are sticky---they adjust only sluggishly in response to supply/demand imbalances. For example, labor contracts that fix the nominal wage for a year or longer magazine prices that publishers change only once every 3-4 years


Prices: Flexible Versus Sticky :Prices: Flexible Versus Sticky The economy’s behavior depends partly on whether prices are sticky or flexible: If prices are sticky, then demand won’t always equal supply. This helps explain unemployment (excess supply of labor) the occasional inability of firms to sell what they produce Long run: prices flexible, markets clear, economy behaves very differently.


Outline of this book: :Outline of this book: Introductory material (chaps. 1 & 2) Classical Theory (chaps. 3-6) How the economy works in the long run, when prices are flexible Growth Theory (chaps. 7-8)The standard of living and its growth rate over the very long run Business Cycle Theory (chaps 9-13)How the economy works in the short run, when prices are sticky.


Chapter summary :Chapter summary Macroeconomics is the study of the economy as a whole, including growth in incomes changes in the overall level of prices the unemployment rate Macroeconomists attempt to explain the economy and to devise policies to improve its performance.


Chapter summary :Chapter summary Economists use different models to examine different issues. Models with flexible prices describe the economy in the long run; models with sticky prices describe economy in the short run. Macroeconomic events and performance arise from many microeconomic transactions, so macroeconomics uses many of the tools of microeconomics.