1. Chapter 2 Thinking Like an Economist
Outline of Topics
T1 The Economist as Scientist
When they are trying to explain the world, they are Scientists
T2 The Economist as Policy Adviser
When they are trying to change the world they are
Policy-makers
T3 Why Economists Disagree

2. T1 The Economist as Scientist
It seem odd to claim that economics is a science because economists do not work with test tubes or telescopes.
However, economists try to address their subject with a scientist’s objectivity. They devise theories, collect data and then analyze these data in an attempt to verify or refute their theories.
Economist and scientist share the same essence of science. That is “the scientific method-the dispassionate development and testing of theories about how the world works.”

3. T 1.1 The role of assumptions
Economists make assumptions because assumption can make the world easier to understand
Economists use different assumptions to answer different questions.
For example, suppose we want to study what happens to the economy when the government changes the number of dollars in circulation. We need to know how prices respond. Then, we need to make different assumptions when studying the effects of the policy change over different time horizons. For studying the short run effect, we assume that prices do not change much; however,

4. T 1.3 First Model: The Circular-Flow Diagram
For studying long run effects, we assume that all prices are completely flexible.
T 1.2 Economic Models
Economists use models to learn about the world, but instead of being made of tangible materials, they are most often composed of diagrams and equations.Economic models omit many details to allow us to see what is truly important.
T 1.3 First Model: The Circular-Flow Diagram
Circular-flow diagram:a visual model of the economy that shows how dollars flow through markets among households and firms. See Figure 2-1 on page 24

5. Two types of decision makers: households and firms
Two types of markets:
The markets for goods and services
The markets for the factors of productions
Factors of production: labour, capital and land
Households own the factors of production & consume all the goods and service that the firms produce
Households are buyers and firms are sellers in the markets for goods and services; however, households are sellers and firms are buyers in the markets for the factors of production.

6. The inner loop of the circular-flow diagram represents the flows of goods and service between households and firms. The households sell the use of their labour, land, and capital to the firms in the markets for the factors of production. The firms then use these factors to produce goods and services, which in turn are sold to households in the market for goods and services. Hence, the factors of production flow from households to firms, and goods and services flow from firms to households.

7. The outer loop of the circular-flow diagram represents the corresponding flow of dollars. The household spend money to buy goods and services form the firms. The firms use some of the revenue from these sales to pay for the factors of production, eg, the wages of their workers. What’s left is the profit of the firm owners, who themselves are members of households. Hence, spending on goods and services flows from households to firms, and income in the form of wages, rent, and profit flows from firms to households.

8. T1.4 Second model: The Production Possibilities Frontier, (PPF, See Figure 2-2 on page 25)
PPF is a graph that shows the various combinations of output that the economy can possibly produce given the available factors of production and technology.
The economy can produce any combination on or inside the frontier. Points outside the frontier are not feasible given the economy’s resources. Points on the PPF represent efficient levels of production. When the economy is producing at such a point, say point A, there is no way to produce more of one good without producing less of the other. Point A & C: feasible and efficient

9. T1.4 PPF
Point B represents an inefficient outcome. For some reason, perhaps widespread unemployment, the economy is producing less than it could from the resources it has available. If the resource of the inefficiency were eliminated, the economy could move from point B to Point A, increasing production of both cars and computers. Point B: feasible but inefficient.
Tradeoffs: moving from point A to point C, society produces more computers (2000 to 2200) but at the expense of producing fewer cars (700 to 600)
Opportunity Cost: moving from point A to point C, society gives up 100 cars to get 200 additional computers. At point A, the opportunity cost of 200 computers is 100 cars.

10. T1.5 Microeconomics & Macroeconomics
T1.4 PPF
A shift in the PPF ( See Figure 2-3 on page 27)
If a technological advance in the computer industry raises the number of computers that a worker can produce per week, the economy can make more of computers for any given number of cars. As a result, the PPF shifts outwards as in Figure 2-3. Because of this economic growth, society might move production from point A to point E, enjoying more computers and more cars.
T1.5 Microeconomics & Macroeconomics
Microeconomics: the study of how households and firms make decisions and how they interact in markets

11. Example: A micro-economist might study the effects of rental control on housing in Victoria or the impact of foreign competition on the Canadian auto industry.
Macroeconomics: the study of economy-wide phenomena, including inflation, unemployment, and economic growth.
Example: A macroeconomist might study the effects of borrowing by the federal government, the changes over time in the economy’s rate of unemployment, or alternative policies to raise growth in national living standards.

12. T2 The Economist as Policy Adviser
T 2.1 Positive Vs.Normative Analysis
Positive statements are descriptive. They make a claim about how the world is
Positive statements or assertions deal with matters of fact or questions about how things are.
Example: “ Minimum-wage laws cause unemployment among the least skilled”
Normative statements are prescriptive. They make a claim about how the world ought to be.
Normative statements reflect individual opinions.
Example: “ The government should raise the minimum wage

13. A key difference between positive and normative statements is how we judge their validity.
In principle, we can confirm or refute positive statements by examining evidence. An economist might evaluate positive statement by analyzing data on changes in minimum wages and changes in unemployment over time.
By contrast, evaluating normative statements involves values as well as facts. Normative statements cannot be judged using data alone. It might also involve our views on ethics, religion, and political philosophy.

14. T3. Why Economists Disagree
The are two basic reasons:
Economists may disagree about the validity of alternative positive theories about how the world works.
Economists may have different values and therefore, different normative views about what policy should try to accomplish
Yet, one should not overstate the amount of disagreement. In many cases, economists do offer a united view.
Proposition 1: A ceiling on rents reduces the quantity and quality of housing available. (93% of Economists agree)
See page 33 for other propositions