Difficulty: Introductory | Prerequisites: Parts 1 and 2 of these notes
Source: Chapter 1, Introduction to Microeconomics (Cengage / Cognero test bank)
This part covers the applied toolkit of Chapter 1: what resources actually are (factors of production), how to think about costs properly (opportunity cost), how rational people make decisions at the margin, how incentives shape behaviour, why people specialise and trade, and how different economic systems answer the three fundamental questions. These concepts underpin every chapter that follows.
Resources (land, labour, capital, entrepreneurship) are scarce, so every choice has an opportunity cost: the value of your best forgone alternative. Rational people make decisions at the margin, comparing the additional benefit of an action against its additional cost. Incentives alter that calculation. People and nations specialise in what they produce at the lowest opportunity cost (comparative advantage) and trade for the rest. Societies answer what, how, and for whom to produce through either markets (prices) or central planning (government).
Factors of production (economic resources)
The four categories of inputs used to produce goods and services: land, labour, capital and entrepreneurship.
Land
All natural resources: soil, water, minerals, oil deposits, timber. A field of corn or an oil deposit is land.
Labour
The physical and mental effort of workers. A person working at a medical testing company is labour.
Capital (physical capital)
Human-made goods used to produce other goods and services: factories, machinery, tools, computers, tractors, assembly lines. In simple terms, capital is the equipment, not the money. Money is not a factor of production because it is not directly used to produce goods.
Human capital
The expertise, knowledge and skills possessed by workers, acquired through education and training. A computer programmer's skill is human capital. A computer is physical capital.
Entrepreneurship
The resource that organises the other factors of production, innovates, and bears the business risk. The entrepreneur does not make the good; they organise, innovate, and take on the risk.
Goods and bads
A good is something people value (garbage removal, automobiles). A bad is something people do not want (garbage, pollution).
Opportunity cost
The highest valued alternative you give up when you make a choice. Think of it as the price of the path not taken. It is subjective: only the person making the choice can determine it.
Marginal benefit
The additional benefit received from one more unit of an action or good.
Marginal cost
The additional cost incurred from one more unit of an action or good.
Rule of rational choice
Undertake an activity if its expected marginal benefit exceeds its expected marginal cost.
Positive incentive
Something that increases benefits or reduces costs, encouraging a behaviour. Example: a scholarship for high grades.
Negative incentive
Something that decreases benefits or increases costs, discouraging a behaviour. Example: a tax on cigarettes.
Comparative advantage
The ability to produce a good at a lower opportunity cost than someone else. In simple terms, comparative advantage is about relative cost, not absolute ability.
Specialization
Devoting resources to one primary productive activity in which you hold a comparative advantage, then trading for the rest.
Consumer sovereignty
Consumers determine what is produced in a market economy through their purchasing decisions ("voting with their dollars").
Market economy
Resources are allocated by individual decision makers responding to market prices.
Command economy
Resources are allocated by a central planning board through political decision making.
Labour-intensive production
Production using large amounts of labour relative to capital. Common in low-wage countries.
Capital-intensive production
Production using large amounts of capital relative to labour. Common in high-wage countries.
The four factors of production are land, labour, capital and entrepreneurship. These are the inputs to all economic activity.
Money (cash, stocks, bonds, chequing accounts) is not a factor of production. It is not directly used to produce goods and services.
Capital means physical capital (tools, machines, buildings), not financial capital. A tractor is capital. A treasury bill is not.
Human capital (skills and knowledge) is distinct from labour (the physical/mental effort itself). Education and on-the-job training add to human capital.
Entrepreneurs organise the other three factors, innovate, and bear risk. Making the good is the job of labour; organising is the entrepreneur's role.
Consumer goods (your new winter tyres) are not factors of production. Factors of production are inputs used to make other goods.
Opportunity cost is the highest valued alternative you sacrifice when you make a choice. Not the sum of all alternatives, just the best one.
It is subjective: only the individual making the choice can determine it, because different people value alternatives differently.
It may or may not involve out-of-pocket (monetary) costs. Forgone wages from not working are an opportunity cost even though you never write a cheque for them.
"There is no such thing as a free lunch" refers to the relationship between scarcity and opportunity cost. Even when something appears free, resources were used and an alternative was given up.
Attending class: if you would otherwise save $10 in parking and earn $20/hour for 3 hours, the opportunity cost of attending class is $70 ($10 + $60).
Attending university: the opportunity cost includes tuition and the value of the student's time (forgone income), but not rent (you would pay rent whether or not you are in school).
Two students at the same school with different job alternatives: the one who gave up a higher-paying job has a higher opportunity cost of attending.
Hotels restricting frequent-stay points during holidays: the opportunity cost to the hotel of filling rooms with points is higher when paying guests are abundant.
The opportunity cost of an airplane flight differs across passengers because both the fare paid and the highest-valued use of travel time vary.
Marginal thinking means comparing the additional (marginal) benefit of one more unit against the additional (marginal) cost of that unit. It is about the next unit, not the total.
The rule of rational choice: undertake an activity if its expected marginal benefit exceeds its expected marginal cost. Stop when MB falls to or below MC.
Rational choices are based on expectations of additional benefits and additional costs, not on totals or the past.
Beer at the stadium costs $16. A rational person stops buying when the marginal benefit of the next beer falls below $16.
Movie tickets cost $8 each. A consumer keeps buying until the marginal benefit of the next ticket drops below $8.
The marginal cost of an additional plate at an all-you-can-eat restaurant is $0 to the patron (you already paid the fixed price), so the rational patron keeps eating until the marginal benefit of one more plate falls to zero.
Croissants priced at $3 for one or $5 for two: the marginal cost of the second croissant is $2 ($5 minus $3).
If the expected marginal benefit of a $62,000 Land Rover is $60,000 to you, the rational choice is not to buy.
Charitable giving is not irrational: the giver derives marginal benefit (satisfaction, altruism) that exceeds the marginal cost.
People respond to incentives in predictable ways. This is a core assumption in economics.
Positive incentives increase benefits or reduce costs (scholarships, subsidies on hybrid cars, tax write-offs).
Negative incentives decrease benefits or increase costs (taxes on cigarettes, fines for hunting, jail sentences for littering in protected areas).
Economic incentives are prices, wages and profits. Non-economic incentives (employee awards, social pressure) exist but are a separate category.
A tax on each child born would, according to economists, reduce the birth rate. A larger tax deduction per child would increase it. Incentives change behaviour.
People specialise to make the best use of resources by devoting themselves to one primary productive activity.
Comparative advantage means the ability to produce at a lower opportunity cost than someone else. It is about relative cost, not about being the best in absolute terms.
Even if you are better at everything (absolute advantage), you should still specialise in the activity where your opportunity cost is lowest and trade for the rest.
Example: a baseball star who is also the best chef in town should not cook his own food. The opportunity cost of his cooking time is enormous because it takes away from his high-earning baseball career.
Countries specialise and trade for the same reason: it frees up resources, allows workers to build skills through repetition, and increases overall production.
Specialization leads to interdependence and the need for trade, not to self-sufficiency.
What goods and services will be produced?
How will they be produced?
For whom will they be produced?
These questions arise because of scarcity. "How can scarcity be eliminated?" is not one of the three, because scarcity cannot be eliminated.
Resources are allocated by individual decision makers responding to market prices.
Consumer sovereignty: consumers determine what is produced by choosing what to buy. Firms respond to those choices.
"For whom" is answered by income and willingness to pay.
"How" is answered by firms seeking the lowest-cost production method. Countries with high labour costs tend to use capital-intensive methods; countries with low labour costs tend to use labour-intensive methods.
Resources are allocated through central planning and political decision making.
The state owns and controls productive capital assets.
The role of markets is replaced by political decision making. It does not guarantee efficiency or equal distribution.
Most real-world economies are mixed, combining elements of both market and command systems.
Students often think money is a factor of production. It is not. Money buys factors of production, but it is not itself used directly in production.
Students often think opportunity cost equals the dollar price of something. It includes all forgone value, monetary and non-monetary (such as forgone time or enjoyment).
Students often confuse marginal thinking with total thinking. Whether to eat a second slice of pizza depends on the marginal benefit and marginal cost of that slice, not on the total cost and benefit of both slices.
Students sometimes think comparative advantage requires being the best at something. It does not. It only requires having the lowest opportunity cost.
⚠️ "Which of the following is NOT a factor of production?" is a very common exam format. Cash, bonds, stocks, legal institutions, private property rights and consumer goods are not factors of production.
⚠️ Opportunity cost calculation questions appear frequently. Remember: it is the best alternative forgone, not the sum of all alternatives.
⚠️ Marginal benefit/cost tables are a staple. You will be given a table and asked how many units a rational consumer buys. The answer: keep going until MB falls below MC (the price).
⚠️ Know the three basic economic questions and that a market system answers all three.
⚠️ Comparative advantage is about lower opportunity cost, not lower absolute cost.
True or false: Cash is a factor of production. (False)
Fill in the blank: The opportunity cost of a choice is the value of the ______ forgone alternative. (highest valued / best)
True or false: A rational person buys another unit as long as its marginal benefit exceeds its marginal cost. (True)
Fill in the blank: The ability to produce at a lower opportunity cost is called ______. (comparative advantage)
True or false: In a command economy, resources are allocated by market prices. (False, by central planning)
Q: What is the opportunity cost of attending class if you would otherwise save $10 parking and earn $20/hour for 3 hours?
A: $70. The $10 parking fee plus $60 in forgone wages.
Q: If the marginal benefit of a cup of coffee is $2.50 and the price is $2.00, what is the net gain from buying it?
A: $0.50. The marginal benefit exceeds the marginal cost by 50 cents.
Q: A subsidy on hybrid cars is what type of incentive?
A: A positive incentive. It reduces the cost of buying a hybrid, encouraging the behaviour.
Q: Why does a baseball star who is also the best cook in town not cook his own food?
A: The opportunity cost of his cooking time is very high because it takes away from his lucrative baseball career. He should specialise in baseball and trade (pay someone else to cook).
Q: What three questions must every society answer?
A: What goods and services to produce, how to produce them, and for whom to produce them.
Q: In a market economy, who determines what is produced?
A: Consumers, through their purchasing decisions (consumer sovereignty).
Opportunity cost is the foundation of the production possibilities frontier (Chapter 2). Marginal thinking reappears in consumer theory (marginal utility) and producer theory (marginal cost of production). Comparative advantage drives the trade chapters. The three basic questions and economic systems set the stage for studying how markets work (supply and demand, Chapters 3-4) and when markets fail (externalities, public goods).
Factors of production, land, labour, capital, physical capital, human capital, entrepreneurship, economic resources, goods and bads, opportunity cost, best forgone alternative, marginal benefit, marginal cost, marginal thinking, rule of rational choice, rational decision, positive incentive, negative incentive, comparative advantage, absolute advantage, specialization, trade, consumer sovereignty, market economy, command economy, mixed economy, three basic economic questions, what how for whom, labour-intensive, capital-intensive, free lunch economics, Chapter 1, Cengage economics