ECOS2001: pass the exams, not just read the notes
Your complete guide to University of Sydney's intermediate microeconomics unit. See where the marks are, work real practice questions, and study with an AI tutor that knows ECOS2001.
Sia generates ECOS2001 practice questions, works through them step by step, and quizzes you on the material the exam weights most heavily.
Worked example
A consumer has Cobb-Douglas utility U(x,y) = x^0.5 y^0.5, income m = 120, and faces prices Px = 4, Py = 6. What is the utility-maximising quantity of x?
For U = x^a y^b, the tangency condition (MRS = price ratio) gives the Cobb-Douglas demand x* = [a/(a+b)]·(m/Px).
x* = 0.5 · (120 / 4) = 0.5 · 30 = 15.
So the optimum is × = 15 (and y* = 0.5·120/6 = 10), which exhausts the budget: 4(15) + 6(10) = 120.
The trap: Spending the whole budget on × (120/4 = 30) ignores that a Cobb-Douglas consumer splits income by the exponent shares. The tangency condition, not a corner, sets the optimum here. classic slip!
One exam decides 50% of your grade. This whole page is built around that.
Overview
What ECOS2001 is, and where it sits
ECOS2001 is the University of Sydney's second-year microeconomics core: it takes the intuition from first year (ECON1001 or BUSS1040) and rebuilds it on formal optimisation. The consumer side runs from budget sets and preferences through utility maximisation, comparative statics and the Slutsky decomposition of a price change into substitution and income effects. The producer side covers technology, profit maximisation, cost curves and competitive supply, before the unit steps up to general equilibrium, choice under uncertainty, and strategic interaction.
The defining shift from first year is rigour: results are derived, not just drawn. You work with marginal-rate-of-substitution conditions, Lagrangian-style first-order conditions, own- and cross-price effects, and equilibrium in an exchange economy. The final third (static and dynamic games, oligopoly and asymmetric information) is where most of the difficulty concentrates and where the 50% final exam weights heaviest.
It is a prerequisite gateway to third-year economics options and to finance and econometrics pathways, so the toolkit here is assumed knowledge downstream.
Official outline: sydney.edu.au · ECOS2001 outline. Always treat the official outline and the exam timetable as authoritative.
Difficulty & time commitment
Is ECOS2001 hard, and how much time does it take?
ECOS2001 is manageable if you keep a weekly rhythm and treat the back half as the main event. The pattern is consistent: it starts gently and steepens, and the heaviest assessment is the part that separates grades.
The difficulty curve and the assessment weighting point the same way: the back half is harder and worth more. Front-loading effort there is the highest-return decision in the unit.
Is this unit for you
Who tends to do well, and who tends to struggle
You will likely do well if
- You are fluent with multivariable calculus: partial derivatives, setting MRS equal to a price ratio, and solving first-order conditions.
- You can move between the algebra and the diagram (indifference curves, isoquants, Edgeworth box) and check one against the other.
- You keep pace with the games-and-information block, because it is the hardest material and the final weights toward it.
You may struggle if
- You treat it like first year and rely on graphs alone; the exams demand derived results, not sketches.
- You leave general equilibrium, uncertainty and game theory to cram, even though they carry the heaviest exam weight.
- You memorise demand formulas without being able to re-derive them from the optimisation problem.
- Re-derive every standard result (Cobb-Douglas demand, the Slutsky equation, Cournot best responses) from first-order conditions rather than memorising the final line.
- Drill the substitution-versus-income-effect decomposition until the signs are automatic.
- Practise past finals timed, since the games and general-equilibrium questions reward speed with the setup.
Syllabus
The 11 topics, topic by topic
The exam-weight marker on each topic shows where the marks concentrate. The amber topics carry the highest exam weight.
T1 · Budget, Preferences & Utility
The budget set, preference axioms, indifference curves and the marginal rate of substitution
T2 · Consumer Choice & Demand
Utility maximisation by tangency/Lagrangian and Cobb-Douglas, substitute and complement demands
T3 · Comparative Statics & Elasticity
Offer and Engel curves, normal/inferior/Giffen goods, and own/cross/income elasticity
T4 · Slutsky, Income Effects & Applications
The substitution vs income effect, endowments, intertemporal choice and labour-leisure
T5 · Exchange Economy & Welfare
The Edgeworth box, Pareto efficiency, the contract curve and the two welfare theorems
T6 · Choices under Uncertainty & Risk
Expected utility, risk attitudes, the certainty equivalent, the risk premium and insurance
T7 · Production: Technology & Profit Maximisation
Production functions, isoquants, the MRTS, returns to scale and cost minimisation
T8 · Costs, Perfect Competition & Partial Equilibrium
The cost-curve family, P=MC, shut-down, long-run zero profit, and surplus with deadweight loss
T9 · General Equilibrium with Production
The PPF, MRT=MRS, Walras' law and the social-planner dual
T10 · Static Games & Oligopoly
Dominance, Nash equilibrium, mixed strategies, Cournot and the monopoly benchmark
T11 · Dynamic Games & Asymmetric Information
Backward induction and SPNE, repeated games, and the lemons market, signalling and moral hazard
How it's assessed
Assessment structure
| Component | Weight | Format & timing |
|---|---|---|
| Attendance / Participation | 5% | Attend and participate in tutorial activities. |
| Online Quizzes ×4 + Early-Feedback Quiz #1 | 20% | Quiz #1 (Early Feedback) due Sat Week 3 (up to 4% of the overall mark); the four quizzes are due Fridays of Weeks 6, 9, 11 and 13 at 11:59pm. Each quiz = 15 randomised MCQs from a large test bank, up to 5 attempts with the highest score kept; no extensions, missed quizzes are reweighted. |
| Mid-semester exam (In-Semester Test) | 25% | In-person paper-based, 60 minutes, closed-book; Sunday 19/04/2026 9:40am (Week 7); 20 MCQ (20 marks) + 1 short-answer with parts a, b (5 marks) = 25 marks; covers Topics 1–5; non-programmable calculator allowed. |
| Final exam | 50% | In-person written (not online), 120 minutes + 10 minutes reading, closed-book; Friday 19 June 2026 9:00am; 20 MCQ × 2 (40 marks) + 3 multi-part short-answer × 20 (60 marks) = 100 marks; covers Topics 6–13 only; non-programmable calculator allowed. |
- Pass on a weighted average of at least 50%. Any component eligibility requirement is noted per component; confirm against the official unit outline.
This is an exam-cram unit. With the exams at 75% of the grade and the final exam alone at 50%, your result is overwhelmingly decided by how well you perform under time pressure.
How to actually pass it
A weekly rhythm, two checklists, and the traps to avoid
The unit rewards consistency over cramming, and practice over re-reading. Here is the loop that works, then what to have nailed before each exam.
The weekly loop
Before the mid-semester checklist
Before the final heaviest topics
- Prioritise the back half: static and dynamic games, oligopoly, asymmetric information and general equilibrium, because the 50% final weights there.
- Rehearse the Slutsky decomposition and comparative statics until the substitution and income terms are instant.
- Practise Cournot and backward-induction problems under time pressure.
- Re-derive competitive supply from cost minimisation so the producer side is not a memorised template.
The mistakes that cost marks
Graphing instead of deriving. Second-year exams ask for the derived optimum with working. A tangency sketch without the first-order conditions loses most of the marks.
Cramming the games block. Static and dynamic games plus asymmetric information are the steepest topics and carry the heaviest final weight; they do not compress into the last week.
Confusing substitution and income effects. The Slutsky decomposition recurs across the unit; getting the sign or direction wrong cascades into wrong comparative statics.
Teaching team
Who teaches ECOS2001
The bios below are factual. We do not rate lecturers; any star ratings are submitted by students who have taken ECOS2001.
Dr Huy Vu
Unit coordinator and lecturer for ECOS2001 in the School of Economics, University of Sydney.
Dr Fangzhou Yu
Lecturer for ECOS2001 in the School of Economics, University of Sydney.
Teaching team as listed in the unit materials reviewed. AskSia does not rate lecturers; star ratings are submitted by students who have taken ECOS2001.
Formula & concept sheet
The vocabulary and formulas you must own
- Marginal rate of substitution (MRS)
- The slope of an indifference curve, MRS = MUx/MUy. At an interior optimum it equals the price ratio Px/Py.
- Cobb-Douglas demand
- For U = x^a y^b, x* = [a/(a+b)]·(m/Px) and y* = [b/(a+b)]·(m/Py): income is split by the exponent shares.
- Slutsky equation
- A price change splits into a substitution effect (movement along an indifference curve) and an income effect (shift to a new curve). Total effect = substitution + income.
- Cost minimisation
- Minimise wL + rK subject to producing output q; at the optimum the marginal rate of technical substitution equals the input price ratio w/r.
- Cournot best response
- Each firm chooses quantity taking rivals' quantities as given; the best response sets marginal revenue equal to marginal cost, and Nash equilibrium is the intersection of best responses.
- Exchange-economy equilibrium
- Prices at which every consumer optimises and all markets clear; efficient allocations lie on the contract curve where MRS is equalised across consumers.
Common acronyms: MRS · MRTS · MU · FOC · GE · NE · MC · MR.
Where it fits
Prerequisites, related units & why it matters
Prerequisite: ECON1001 or BUSS1040 (introductory microeconomics). Quantitative-methods corequisites are commonly taken alongside. Prohibited with ECON2001, ECON2901 or ECOS2901.
Your ECOS2001 study toolkit
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FAQ
Frequently asked questions
Is ECOS2001 hard?
It is moderate-to-hard for a second-year unit. The step up from first year is formal optimisation and calculus, and 75% of the grade sits in two in-person exams with the 50% final weighting toward the harder games, uncertainty and general-equilibrium material.
How is ECOS2001 assessed?
Attendance and participation (5%), online quizzes plus an early-feedback quiz (20% combined), a 25% in-semester mid-term exam, and a 50% final exam. You pass on a weighted average of at least 50%.
How much maths is involved?
A lot for an economics unit: partial derivatives, constrained optimisation via first-order conditions, the Slutsky equation, cost minimisation and game-theory best responses. It is calculus-based rather than purely graphical.
What background do I need?
First-year microeconomics (ECON1001 or BUSS1040) and comfort with calculus. The unit assumes the first-year toolkit and rebuilds it formally.
What is the hardest part?
The final third: static and dynamic games, oligopoly and asymmetric information, plus general equilibrium. It is the most abstract material and the most heavily examined.
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