MGEA02H3 Introduction to Microeconomics: A Mathematical Approach
The Complete Exam Bible · Fall 2026MGEA02H3 Overview
- University of Toronto Scarborough
- Fall 2026
- First-year Economics
- In-person final exam
What the course covers
MGEA02H3 is the University of Toronto Scarborough’s first course in microeconomics taught with mathematics.
- Assessed by Online assignments, one midterm and a two-hour final worth half the grade.
- Core method Write the equation, solve it, then explain the economic mechanism in a sentence.
- Hardest step Turning a cost or utility function into the right marginal condition.
- How to prepare Rework past-paper question types with new numbers rather than memorising answers.
How MGEA02H3 is assessed
| Component | Weight | Format |
|---|---|---|
| Assignments (best 5 of 6) | 20% | Online assignments; due dates posted on Quercus |
| Midterm | 30% | 1 hour 30 minutes; in person, outside class time |
| Final Exam | 50% | Two hours; in person in the final exam period |
The Fall 2026 outline weights total 100%. If you write both tests and score higher on the final, part or all of the midterm weight moves to the final; the outline and the course handbook word this rule differently, so confirm it on Quercus.
Assessment structure
Segment widths reproduce the three published weights, which total 100%.
Current MGEA02H3 dates
| Date | Item | Control |
|---|---|---|
| Sunday, September 27, 2026 | Assignment 1 due | Online; by 11:45 p.m. as posted on Quercus |
| Sunday, October 11, 2026 | Assignment 2 due | Online; by 11:45 p.m. as posted on Quercus |
| Sunday, October 25, 2026 | Assignment 3 due | Online; by 11:45 p.m. as posted on Quercus |
| Sunday, November 15, 2026 | Assignment 4 due | Online; by 11:45 p.m. as posted on Quercus |
| Sunday, November 29, 2026 | Assignment 5 due | Online; by 11:45 p.m. as posted on Quercus |
| Tuesday, December 8, 2026 | Assignment 6 due and last day of term | Last day to submit term work |
| December 10 to 22, 2026 | Final exam period | Exact date set in the exam timetable |
Dates are as published in the Fall 2026 course outline and the Quercus course page. Confirm exact deadlines and submission settings in the live LMS.
What MGEA02H3 covers
Eleven chapters follow the Fall 2026 reading list from production possibilities to international trade.
Production Possibilities and Opportunity Cost
Classify bundles against the frontier, compute opportunity cost from its slope and find the value-maximising pointOne curve for scarcity and choice
The first topic of the course uses the production possibilities frontier to make scarcity, efficiency and trade-offs concrete.
- Efficient, inefficient and unattainable bundles
- Opportunity cost as minus the frontier slope
- Increasing opportunity cost on a bowed-out frontier
- Constant cost on a linear frontier
- Value-maximising output at given prices
- Shifts and pivots after technical change
Supply, Demand and Price Controls
Shift the correct curve, solve linear equilibrium and trace ceilings, floors and black-market pricesMarkets in equations
The course writes demand and supply as equations in either price form or quantity form and solves equilibrium by equating them.
- Movement along a curve versus a shift
- Determinants absorbed into the demand intercept
- Solving linear equilibrium algebraically
- Simultaneous shifts and ambiguous outcomes
- Binding price ceilings and black markets
- Price floors, minimum wages and quotas
Utility, Consumer Demand and Surplus
Apply the optimal purchase rule, compute consumer surplus and price a flat feeFrom utility to demand
Utility in the course is measured in dollars, so consumer surplus is total utility minus spending.
- Marginal utility as the derivative of utility
- The optimal purchase rule MU = P
- Consumer surplus as U(X) − U(0) − PX
- Horizontal summation of individual demands
- Flat fees and the maximum access charge
- Kinked demand curves and split areas
Elasticity and Excise Taxes
Measure point elasticity, link it to revenue and split a per-unit tax between buyers and sellersPoint elasticity the course way
Elasticity is measured with the calculus point formula, ED = |(dQ/dP)(P/Q)|, inverting the slope when the curve is written in price form.
- Point elasticity of demand and supply
- Elasticity along a linear demand curve
- Total revenue and elasticity
- Tax incidence and the ES/ED ratio
- Tax revenue and excess burden
- The revenue-maximising tax
Production and Diminishing Marginal Returns
Derive marginal and average product with a fixed plant and convert them into marginal and average variable costProductivity with a fixed plant
In the short run capital is fixed, so output changes only with labour. Marginal product is dQ/dL and average product is Q/L.
- Total, marginal and average product
- The law of diminishing marginal product
- Marginal product crossing average product
- Marginal cost as wage over marginal product
- Average variable cost as wage over average product
- Labour requirement functions
Short-Run and Long-Run Costs
Build every short-run cost curve, find shut-down and break-even prices and read the long-run envelopeShort-run cost curves
Total cost splits into fixed and variable cost, and the per-unit curves follow: average fixed cost falls throughout, average variable and average cost are U-shaped, and marginal cost crosses both at their minima.
- Fixed, variable and total cost
- Average and marginal cost curves
- Shut-down and break-even prices
- Stated fixed cost versus the TC constant
- Long-run average cost as an envelope
- Economies of scale and minimum efficient scale
Perfect Competition and Industry Supply
Set price equal to marginal cost, test the shut-down rule and trace entry and exit to the long runThe price-taking firm
A perfectly competitive firm faces a horizontal demand curve at the market price, so marginal revenue equals price and output is chosen where P = MC.
- Price taking and P = MR = MC
- Shut-down and break-even prices
- Short-run firm and industry supply
- Long-run entry, exit and zero profit
- A per-unit tax in the short and long run
- Efficiency of competitive equilibrium
Monopoly and Market Power
Solve MR = MC, read price from demand, measure the deadweight loss and compare regulation rulesRestricting output
A monopolist faces market demand, so marginal revenue lies below price: for P = a − bQ, MR = a − 2bQ. It produces where MR = MC and charges the price buyers will pay for that quantity, read from demand.
- Marginal revenue below demand
- MR = MC and price from demand
- Monopoly and elasticity
- Gain to society and deadweight loss
- Average-cost and marginal-cost regulation
- A per-unit tax on a monopolist
Oligopoly and Game Theory
Fill a duopoly payoff matrix, find dominant strategies and the Nash outcome and explain why cartels break downStrategic interaction
In an oligopoly a few firms each depend on the others’ choices. The course models a duopoly with a payoff matrix: each cell gives each firm’s profit at the combined output, assuming each firm takes its rival’s output as given.
- Payoff matrices for a duopoly
- Dominant strategies and Nash equilibrium
- Joint-profit maximisation and cartels
- Why collusion breaks down
- Algebraic duopoly with linear demand
- Ranking welfare across market structures
Externalities and Public Goods
Add external cost to supply, set a corrective tax and sum marginal benefits for a public goodExternal costs
An externality is an effect on third parties that the market price ignores. With pollution, marginal social cost is private marginal cost plus marginal external cost, MEC = dTEC/dQ.
- Marginal external and marginal social cost
- Overproduction and deadweight loss
- The corrective tax and its excess burden
- Public goods and vertical summation
- The free-rider problem
- Abatement taxes and tradable permits
International Trade, Tariffs and Quotas
Find comparative advantage, compute imports at the world price and measure the cost of a tariffComparative advantage
A country has a comparative advantage in the good it produces at the lower opportunity cost, even if another country is more productive in both goods.
- Absolute and comparative advantage
- Gains from specialisation and trade
- Imports at the world price
- Tariff revenue and efficiency loss
- Prohibitive tariffs and long-run imports
- Quotas compared with tariffs
The Fall 2026 outline describes microeconomics as the study of how scarcity shapes the choices of individual decision makers, how markets and prices allocate resources, and how policy changes that allocation.
The topics run from production possibilities and opportunity cost, through supply and demand, consumer utility, elasticity and excise taxes, to production, short-run and long-run costs, and then to market structure: perfect competition, monopoly and oligopoly.
The term closes with market failures, externalities and public goods, and with international trade.
Why the mathematics matters
The prerequisite is high school calculus and algebra, and extra mathematical material is introduced in class.
In practice that means demand and supply written as equations and solved for equilibrium, opportunity cost found as minus the slope of a frontier, marginal utility and marginal cost found by differentiation, surplus measured as triangle areas, and the monopolist’s output found from MR = MC.
Students who can describe a graph but not solve the algebra behind it lose marks on the computational questions that dominate past tests.
How the guide is organised
Eleven chapters follow the reading list in order.
Each chapter starts from a figure drawn to its own numbers, works an original example step by step, gathers the course formulas in one box, and ends with practice items written to the question types that recur in the course’s past tests and finals, with new numbers.
The final chapter reuses earlier tools, which reflects the cumulative design of the final exam.
Assessment at a glance
The best five of six online assignments count for 20%, a 90-minute in-person midterm for 30% and a two-hour final exam for 50%. The improvement rule for students whose final mark beats their midterm mark is worded differently in two places, so confirm on Quercus how it is applied.
Worked example · free
Monopoly output, price and deadweight loss
- 2Marginal revenue is 120 − 4Q; setting it equal to 20 gives Q = 25.
- 2Price from demand is $70, so profit is (70 − 20) × 25 = $1,250.
- 2Competition would produce 50 units, so the lost triangle is ½ × 25 × 50 = $625.
Key terms
- Scarcity
- Scarcity is the condition of having limited resources with competing uses, which forces choices.
- Opportunity Cost
- Opportunity cost is the value of the best alternative given up when a choice is made.
- Market Equilibrium
- Market equilibrium is the price and quantity at which quantity demanded equals quantity supplied.
- Consumer Surplus
- Consumer surplus is the value buyers place on the units they buy minus what they pay.
- Producer Surplus
- Producer surplus is the revenue sellers receive above the minimum they would accept, measured above the supply curve.
- Point Elasticity
- Point elasticity is the responsiveness of quantity to price at one point on a curve, computed as (dQ/dP)(P/Q).
- Excess Burden
- Excess burden is the loss of surplus from a tax beyond the revenue it raises.
- Marginal Cost
- Marginal cost is the additional cost of producing one more unit of output.
- Shut-Down Price
- The shut-down price is the lowest price at which a firm covers its average variable cost.
- Marginal Revenue
- Marginal revenue is the additional revenue from selling one more unit.
- Nash Equilibrium
- A Nash equilibrium is an outcome in which each player’s choice is best given the other’s choice.
- Comparative Advantage
- Comparative advantage is producing a good at a lower opportunity cost than a trading partner.
MGEA02H3 FAQ
What is the final exam format?
The Fall 2026 outline states a two-hour final exam written in person during the final exam period, worth 50% of the grade, and the course handbook says it covers material from the whole term. Recent past finals combined a multiple-choice section with two longer short-answer questions. Confirm the exact Fall 2026 structure on Quercus and in class.
How much is the midterm worth and how long is it?
The midterm is worth 30% and lasts 1 hour 30 minutes, written in person outside class time. Its date is announced in class and on Quercus. There is no make-up midterm; with a documented legitimate absence, the weight can move to the final if the request is made within two weeks.
How do the online assignments count?
There are six online assignments and the best five count for 20% of the grade. Late assignments are not accepted under any circumstance, so the dropped assignment is a safety margin rather than a planned skip. Due dates are posted on Quercus.
What calculator can I use in the tests?
Non-programmable calculators are allowed. Calculators with considerable text storage, such as graphing calculators, will be confiscated during an exam, and having an unauthorized electronic device such as a phone during an exam violates the Code of Behaviour on Academic Matters.
How much mathematics does the course use?
The prerequisite is high school calculus and algebra, and extra mathematical material is introduced in class. Expect to solve linear equations for equilibrium, differentiate utility, production and cost functions, compute areas of surplus triangles, and set marginal revenue equal to marginal cost.
How should past papers be used for revision?
The course page holds many years of past tests and finals with answer files. Use them to learn which question types recur and which traps the options are built from, then practise those types with new numbers. Treat their timing with care, because past finals ran longer than the two hours stated for Fall 2026.
Which topics are hardest to get right?
Students most often slip on cost questions that state a fixed cost different from the constant in total cost, on reading a monopoly price from marginal revenue instead of demand, and on tax questions that tempt them to think the legal payer decides who bears the tax.
Questions students ask in each MGEA02H3 chapter
- Why is the opportunity cost zero at a point inside the frontier?
- Inside the frontier some resources are idle or poorly used, so output of one good can rise without reducing the other. Nothing has to be sacrificed until the economy reaches the frontier, which is why a slope should not be quoted for an inside point. Chapter 01 · Production Possibilities and Opportunity Cost
- How can I tell whether a ceiling actually binds?
- Solve the equilibrium first. A ceiling binds only if it is below the equilibrium price, and a floor only if it is above. A non-binding control changes nothing, and an option reporting a shortage at a non-binding ceiling is a distractor. Chapter 02 · Supply, Demand and Price Controls
- Why is the marginal utility curve the same as the demand curve?
- The consumer buys until marginal utility equals price. At every possible price, the quantity chosen is the one whose marginal utility matches that price, so plotting those pairs traces the marginal utility schedule itself. Chapter 03 · Utility, Consumer Demand and Surplus
- Does it matter whether buyers or sellers pay the tax to the government?
- No. Shifting supply up or demand down by the same tax produces the same quantity, the same two prices and the same revenue. Only the elasticities of demand and supply decide who bears the burden. Chapter 04 · Elasticity and Excise Taxes
- Why must one input be fixed for diminishing returns?
- Diminishing marginal product describes adding more of one input to a fixed amount of another. If every input could grow together, workers would not have to share equipment, so the law is a short-run idea. Chapter 05 · Production and Diminishing Marginal Returns
- Why does marginal cost cut average cost at its minimum?
- When marginal cost is below average cost, each extra unit pulls the average down; when it is above, the average rises. The average is therefore lowest exactly where the two are equal. Chapter 06 · Short-Run and Long-Run Costs
- Why does a firm keep producing while it makes a loss?
- If price covers average variable cost, producing earns enough to pay every avoidable cost and part of the fixed cost. Shutting down would leave the whole fixed cost unpaid, so operating gives the smaller loss. Chapter 07 · Perfect Competition and Industry Supply
- Why is a monopolist’s marginal revenue below its price?
- To sell one more unit the monopolist must lower the price on every unit it sells, not just the last one. The revenue lost on the earlier units is subtracted from the price of the extra unit. Chapter 08 · Monopoly and Market Power
- Why is the Nash outcome not the cell with the highest total profit?
- The stable cell is the one no firm wants to leave given its rival’s choice. At the highest-total cell each firm can gain by producing more while its rival holds back, so that cell is not stable. Chapter 09 · Oligopoly and Game Theory
- Does a negative externality cause too much or too little output?
- Too much. The market ignores the external cost, so it produces where demand meets private supply, beyond the point where demand meets marginal social cost. Units in between cost society more than buyers value them. Chapter 10 · Externalities and Public Goods
- Can a country gain from trade if it is less productive in both goods?
- Yes. Gains depend on comparative advantage, which compares opportunity costs. A country that is less productive in everything still has a lower opportunity cost in one good and gains by specialising in it. Chapter 11 · International Trade, Tariffs and Quotas
How to study for the exam
Revise in three passes. First, rebuild each chapter from memory: write the defining equation, draw the graph with labelled axes and state the rule that connects them, such as MU = P, P = MC or MR = MC. Second, solve a new numerical case for every chapter, keeping units and signs on each line and checking the answer against a second route, such as the area under a curve or an elasticity identity.
Third, mix topics, because the final is cumulative: a tariff question needs surplus areas, a monopoly question needs elasticity, and an externality question reuses competitive equilibrium. Use the past papers on the course page to learn the recurring question types and the traps their wrong options are built from, then practise those types with your own numbers rather than memorising the keyed answers.
Keep an error log grouped by mistake, for example fixed cost confused with the constant, price read from marginal revenue, or a slope quoted for a point inside the frontier, and rework each entry a few days later. In the final week, sit timed mixed sets within two hours and practise writing one clear sentence of explanation after each calculation.
Your AI Economics tutor for MGEA02H3
Stuck on a hard MGEA02H3 question? Sia is AskSia’s AI Economics tutor — ask any MGEA02H3 Introduction to Microeconomics: A Mathematical Approach question and get a clear, step-by-step explanation grounded in how the course is actually taught and assessed. Read this whole study guide free, then take your hardest questions to Sia.
