ECO 301: Advanced Microeconomics Study Pack (South African Universities, Colleges & TVETs)

Advanced Microeconomics (often coded as ECO 301 or equivalent in South African Commerce/Economics programmes) is where students move beyond basic supply-and-demand intuition into rigorous analysis of consumer choice, firm behaviour, market equilibrium, welfare, game theory, and advanced market structures. This study pack is written to help you prepare for assessments at South African universities, colleges, and TVETs—with emphasis on how lecturers and examiners commonly test microeconomics at honours and senior-undergraduate level. It combines concept-building, exam-style problem-solving frameworks, and institutionally relevant study habits for institutions where ECO 301-style content is taught.

Because ECO 301 syllabi differ by institution, this pack is designed as a master set of methods you can adapt to your module guide. You’ll find (1) the core models you must master, (2) the typical South African exam question patterns, and (3) worked examples that you can replicate under time pressure. It’s structured into five substantial sections, each adding a layer of micro theory and exam technique.

1) ECO 301 Foundations: Preferences, Utility, and Constrained Choice (with SA Exam Problem Patterns)

Core idea: From preferences to demand

Advanced microeconomics starts with a formal representation of consumer preferences and then derives demand from optimisation. You should be comfortable with the following logic chain:

1. Preferences are represented by a utility function (u(x_1, x_2)).
2. Preferences axioms (completeness, transitivity, continuity, convexity) justify the existence of a maximisation problem.
3. Constrained choice: the consumer chooses the bundle that maximises utility subject to a budget constraint.

The standard optimisation problem is:

[
\max_{x_1,x_2} u(x_1,x_2) \quad \text{s.t.} \quad p_1x_1+p_2x_2 \le I
]

where (p_1, p_2) are prices and (I) is income.

Lagrangian approach (most exam-friendly):
[
\mathcal{L} = u(x_1,x_2) + \lambda(I – p_1x_1 – p_2x_2)
]
First-order conditions typically lead to:
[
\frac{\partial u/\partial x_1}{\partial u/\partial x_2}=\frac{p_1}{p_2}
]
and the budget binds at optimum when utility is monotonic.

Functional forms you must handle

1) Cobb–Douglas utility

A common exam utility:
[
u(x_1,x_2)=x_1^{\alpha}x_2^{1-\alpha}, \quad 0<\alpha<1
]
Demand is:
[
x_1^=\alpha\frac{I}{p_1}, \qquad x_2^=(1-\alpha)\frac{I}{p_2}
]

Why this matters for tests: you can quickly compute Marshallian demand without heavy algebra.

2) Perfect substitutes and complements (boundary solutions)

• Perfect substitutes: (u=x_1+x_2) ⇒ the consumer buys only the cheaper good.
• Perfect complements: (u=\min{ax_1,bx_2}) ⇒ fixed proportion bundles.

Exams often ask for corner solutions and reasoning using indifference curves.

Slutsky decomposition and income/substitution effects

If the price of good 1 changes from (p_1) to (p_1'), you decompose the change in Marshallian demand into:

• Substitution effect (relative price effect holding purchasing power constant)
• Income effect (effect due to real purchasing power change)

The Slutsky equation (for good 1):
[
\frac{\partial x_1}{\partial p_1}=\frac{\partial h_1}{\partial p_1}-x_1\frac{\partial x_1}{\partial I}
]
where (h_1(p_1,p_2,I)) is Hicksian (compensated) demand.

Exam skill: Many students know the words but can’t apply the equation. Practice setting up the decomposition for at least one numerical example.

Elasticities and log-utility exam moves

Elasticities are common in ECO 301-type problems, especially in applied settings (taxes, price controls, welfare). For Cobb–Douglas, expenditure shares are constant: good 1 share is (\alpha). That implies:

• Expenditure elasticity is 1.
• Own-price elasticity for Cobb–Douglas is (-1) (in the typical two-good case with share (\alpha)).

You should be able to justify such results quickly.

Worked mini-case (exam style): Budget line and optimal bundle

Question pattern:
A student has income (I=R10,000). Prices are (p_1=R50), (p_2=R100). Utility is Cobb–Douglas (u=x_1^{0.4}x_2^{0.6}).

Step 1: write demands
[
x_1^=0.4\frac{10,000}{50}=0.4\cdot 200=80
]
[
x_2^=0.6\frac{10,000}{100}=0.6\cdot 100=60
]

Step 2: check budget
[
50(80)+100(60)=4,000+6,000=10,000
]
Budget constraint binds.

What examiners like: clear demonstration that the budget is exhausted at optimum and correct substitution of parameters.

South African assessment habits to prepare for

While course titles vary across institutions, South African economics assessments at this level typically reward:

• Clean mathematical setups (Lagrangian, Kuhn–Tucker for constraints).
• Interpretation of results (economic meaning of signs of derivatives).
• Unit clarity (prices in rands, quantities in units).
• Welfare reasoning (consumer surplus, compensating variation when relevant).

Build your answer style around those.

2) Advanced Production, Costs, and Firm Optimisation (including South Africa-linked applications)

Production functions and marginal analysis

Firms choose inputs to maximise profit (or minimise cost). You must master the basics of production functions:

[
q = f(L,K)
]

where (L) is labour, (K) is capital. Core objects:

• Marginal products: (MP_L=\partial f/\partial L), (MP_K=\partial f/\partial K)
• Diminishing marginal returns under common assumptions

For isoquant analysis, the firm uses an input choice condition similar to consumer equating marginal rates:
[
\frac{MP_L}{MP_K}=\frac{w}{r}
]
where (w) is wage and (r) is rental rate of capital.

Cost minimisation vs profit maximisation

Two equivalent ways to define firm behaviour:

1. Cost minimisation: For a given output (q), choose (L,K) to minimise cost:
   [
   \min_{L,K} wL+rK \quad \text{s.t.} \quad f(L,K)\ge q
   ]
   This yields the cost function:
   [
   C(q,w,r)
   ]

2. Profit maximisation: Choose output and inputs to maximise:
   [
   \max \ \pi = pq – C(q,w,r)
   ]

Often, ECO 301 assessments focus on using cost functions to derive supply and marginal cost.

Marginal and average cost relationships

Given cost function (C(q)):

• Average cost: (AC(q)=\frac{C(q)}{q})
• Marginal cost: (MC(q)=C'(q))

A key calculus relationship:

• When (MC<AC), average cost falls.
• When (MC>AC), average cost rises.
• (MC=AC) at the minimum of (AC).

Examiners frequently use this to test graph reasoning and sign logic.

Example: Deriving marginal cost and optimal output

Suppose a firm has total cost:
[
C(q)=20q+q^2
]
Then:
[
MC(q)=C'(q)=20+2q
]
If the firm faces product price (p=R60) and assuming no fixed cost issues affect output choice, profit:
[
\pi(q)=60q-(20q+q^2)=40q-q^2
]
First-order condition:
[
\pi'(q)=40-2q=0 \Rightarrow q^*=20
]
Profit:
[
\pi(20)=40(20)-400=800-400=R400
]

This is the simplest “price equals marginal cost” style outcome.

Short-run vs long-run and economies of scale

• Short run: at least one factor fixed (usually capital).
• Long run: all factors variable.

Economies of scale: if long-run average cost decreases with output.
Diseconomies of scale: if it increases.
Constant returns to scale: long-run average cost constant.

A typical exam reasoning approach:

1. Identify if returns to scale increase/decrease.
2. Translate to long-run cost behaviour.
3. Use the conclusions to interpret market structure implications (natural monopolies, entry barriers).

Market power and cost structure (why this is “advanced”)

Advanced micro requires you to see that costs affect pricing strategies and market outcomes. For example:

• If a firm has strong fixed costs, it may price differently (e.g., to cover fixed cost in monopolistic competition).
• In natural monopoly settings (high scale economies), marginal cost pricing may not cover average costs.

Numerical case connected to real-world policy thinking

Consider a utility-like firm where fixed costs are high and variable costs are moderate. Suppose:
[
C(q)=2000+50q+\frac{1}{2}q^2
]
Then:
[
MC(q)=50+q
]
If regulator sets price equal to marginal cost (p=MC(q)), we solve for (q) such that demand equals supply given price. If demand is linear:
[
Q(p)=100-p
]
Set (p=50+q) but (q=Q(p)). Alternatively solve using demand in terms of price:
[
q=100-p
]
Substitute (p=50+q):
[
q = 100-(50+q)=50-q \Rightarrow 2q=50 \Rightarrow q=25
]
Then (p=50+25=75). Total cost:
[
C(25)=2000+50(25)+\frac{1}{2}(25^2)=2000+1250+312.5=R3,562.50
]
Revenue:
[
R=75(25)=R1,875
]
Profit is negative. This shows why marginal cost pricing can require subsidies when fixed costs are large.

Exam payoff: you can convert cost logic into policy implications, which many ECO 301 instructors emphasise in essays.

3) Partial Equilibrium, Welfare, and Market Failures (Taxes, Transfers, Externalities, Public Goods)

Welfare foundations: consumer and producer surplus

In partial equilibrium, welfare analysis often uses:

• Consumer surplus (CS): willingness to pay above market price.
• Producer surplus (PS): market price above marginal cost (or supply curve).

For a linear demand (D(p)=a-bp) and linear supply (S(p)=c+dp), you can compute equilibrium price and quantities, then calculate CS/PS using triangle areas.

General exam steps:

1. Find equilibrium by setting quantity supplied equal to quantity demanded.
2. Compute equilibrium price (p^) and quantity (q^).
3. Model policy shock (tax, subsidy, price control, quota).
4. Derive new equilibrium and compute deadweight loss (DWL).

Incidence of a tax: who pays?

Tax incidence depends on elasticities, not on statutory responsibility.

For a small per-unit tax (t):

• The buyer price becomes (p_b = p + t_b)
• The seller price becomes (p_s = p – t_s)
• The wedge between buyer and seller price equals tax (t)

In standard linear models, you can compute the tax wedge and determine how the tax divides:

• If demand is more inelastic than supply, buyers bear more of the tax.
• If supply is more inelastic, sellers bear more.

South African relevance: policy questions often appear in micro exams (e.g., VAT effects in general equilibrium are beyond ECO 301, but partial equilibrium tax incidence frequently appears as a conceptual essay question).

Worked example: unit tax with linear demand and supply

Suppose:
[
Q_d = 120 – 2p
]
[
Q_s = 20 + p
]
Equilibrium without tax: set equal:
[
120 – 2p = 20 + p \Rightarrow 100 = 3p \Rightarrow p^* = 33.\overline{3}
]
Quantity:
[
q^* = 20 + 33.\overline{3}=53.\overline{3}
]

Now introduce per-unit tax (t=10) that creates wedge between buyer and seller prices. Let buyer price be (p_b), seller price be (p_s), with:
[
p_b = p_s + 10
]
Demand depends on buyer price:
[
Q_d = 120 – 2p_b
]
Supply depends on seller price:
[
Q_s = 20 + p_s
]
Equate:
[
120 – 2(p_s+10) = 20 + p_s
]
[
120 – 2p_s – 20 = 20 + p_s
]
[
100 – 2p_s = 20 + p_s
]
[
80 = 3p_s \Rightarrow p_s = 26.\overline{6}
]
Then:
[
p_b = 36.\overline{6}
]
Quantity with tax:
[
q_t = 20 + 26.\overline{6}=46.\overline{6}
]

Deadweight loss logic: quantity falls from (53.\overline{3}) to (46.\overline{6}). DWL is the value of lost gains from trade that are not captured by government.

Even if your exam does not require exact DWL calculations, the elasticities and wedge logic must be articulated clearly.

Externalities: negative and positive

Externalities occur when social marginal cost/benefit differs from private marginal cost/benefit.

Negative externality (e.g., pollution)

Let social cost be higher:
[
MSC = MPC + MEC
]
A tax equal to the external marginal cost at the efficient quantity can achieve efficiency.

In a linear example:

• Private supply reflects MPC
• Social supply reflects MSC

Efficient quantity is where:
[
D = MSC
]
Market quantity where:
[
D = MPC
]
Thus market output exceeds efficient output under negative externalities.

Positive externality (e.g., education, vaccination)

Let:
[
MSB = MPB + MEB
]
Underproduction relative to efficient output occurs.

Exam technique: Always state which curve shifts (in partial equilibrium diagrams):

• Negative externality: supply shifts upward (to social supply).
• Positive externality: demand shifts upward (to social demand).

Public goods and free-riding

A public good is non-excludable and non-rival. In standard models, efficient provision requires Samuelson’s condition:
[
\sum_i MB_i = MC
]

For example, with two consumers valuing the good at different marginal benefits, the socially optimal quantity accounts for both valuations simultaneously.

Free-riding argument (common essay item):

• Individuals have incentive to underreport preferences.
• Market underprovides due to inability to charge efficiently.

In ECO 301, this can appear as:

• A diagram/inequality question.
• A short essay asking to explain consequences and policy solutions.

Cost-benefit, efficiency, and distributional concerns

Welfare in ECO 301 often focuses on efficiency (total surplus). But many exam questions ask to discuss:

• Efficiency trade-offs
• Equity/distributional concerns
• Constraints and political economy

Good exam answers explicitly distinguish:

• Efficiency criterion: minimise deadweight loss / maximise total surplus.
• Distribution criterion: who gains and who loses.

Quantitative welfare with compensating variation (CV) and equivalent variation (EV)

When policy changes prices, you can express welfare change in money-metric terms.

• Compensating variation (CV): amount paid to keep consumer at initial utility after price change.
• Equivalent variation (EV): amount required to give consumer the new price utility with initial prices.

Exams may not require full derivations for general utility, but you should be able to explain:

• CV and EV align under small changes.
• CV > 0 typically when a price increase reduces welfare.

4) Market Structures and Strategic Behaviour: Monopoly, Oligopoly, and Game Theory Entry Points

Monopoly: pricing, markup, and deadweight loss

A monopolist chooses quantity (q) such that:
[
MR(q) = MC(q)
]
Given a downward-sloping demand curve (p(q)), marginal revenue lies below demand (for non-linear demand).

Markup rule (elasticity-based):
[
\frac{p-MC}{p} = -\frac{1}{\varepsilon}
]
where (\varepsilon) is the demand elasticity (absolute value). The less elastic demand is, the larger the markup.

Exam pattern: provide demand elasticity and ask for implied markup or compare two markets.

Worked monopoly example with numbers

Let demand:
[
p(q)=100-q
]
Then total revenue:
[
TR(q)=p(q)q=(100-q)q=100q-q^2
]
Marginal revenue:
[
MR(q)=100-2q
]
Let cost:
[
C(q)=20q
\Rightarrow MC=20
]
Set (MR=MC):
[
100-2q=20 \Rightarrow 2q=80 \Rightarrow q_m=40
]
Price:
[
p_m=100-40=60
]
Competitive equilibrium if marginal cost equals price: (p=MC=20) with demand (20=100-q \Rightarrow q_c=80). Monopoly restricts output and increases price.

Price discrimination and regulation

ECO 301 may also cover:

• First-degree discrimination: captures all CS.
• Second-degree discrimination: menus and quantity discounts.
• Third-degree discrimination: different prices across groups with different elasticities.

If you’re given separate demands for two consumer types, the optimal discriminatory policy solves:
[
MR_1 = MC,\quad MR_2 = MC
]
or sets prices to equate marginal revenue to marginal cost separately, respecting incentive constraints.

In regulation questions, you might be asked about:

• Price caps
• Marginal cost pricing
• Two-part tariffs

Oligopoly and strategic interaction: introduction to Nash equilibrium

Advanced micro transitions into strategic games:

• Players
• Actions
• Payoffs
• Nash equilibrium: no unilateral profitable deviation.

A basic 2×2 example structure you should master is:

	Firm B: L	Firm B: R
Firm A: U	(a,a)	(b,c)
Firm A: D	(c,b)	(d,d)

(Your numbers change per exam question, but the reasoning is identical.)

Dominant strategies and iterated elimination (IESDS)

If a player has a dominant strategy, equilibrium may be found quickly.

• Dominant strategy: yields higher payoff regardless of opponent action.
• Iterated elimination of dominated strategies: repeatedly remove dominated strategies until stable.

Many exam questions ask:

1. Identify dominated strategies.
2. Remove them.
3. State equilibrium (possibly multiple equilibria).

Prisoner’s Dilemma and collusion incentives

The prisoner’s dilemma is the canonical illustration:

• Competitive behaviour is stable (Nash equilibrium).
• Joint optimum requires collusion, but collusion isn’t stable if unilateral deviation gains.

In diagrams, show:

• Payoffs for “Cooperate/Defect”
• Equilibrium at Defect/Defect
• Pareto superior outcome at Cooperate/Cooperate

Exam essay prompts often ask:

• Explain why repeated interaction can support cooperation.
• Discuss role of discount factor (future payoffs).

Cournot and Stackelberg models (quantity vs timing)

Cournot:

• Firms choose quantities simultaneously.
• Each firm assumes the other’s quantity fixed.
• Outcome depends on number of firms and reaction functions.

Stackelberg:

• Leader commits to quantity first.
• Follower reacts optimally.
• Leader advantage can produce higher profits for leader.

Core exam skills:

• Set up reaction functions.
• Solve simultaneously (Cournot) or sequentially (Stackelberg).
• Compute equilibrium quantities, prices, and profits.

Worked Cournot example

Two firms with identical cost (C_i(q_i)=cq_i) and inverse demand:
[
p(Q)=a-Q, \quad Q=q_1+q_2
]
Firm (i) profit:
[
\pi_i = (a-q_1-q_2)q_i – c q_i
]
Reaction function for firm 1 given (q_2):
[
\pi_1 = (a – q_2 – q_1)q_1 – cq_1
]
[
= (a-q_2)q_1 – q_1^2 – cq_1
]
[
\frac{\partial \pi_1}{\partial q_1} = (a-q_2) – 2q_1 – c=0
]
[
2q_1 = a-q_2-c
\Rightarrow q_1 = \frac{a-c-q_2}{2}
]
Similarly:
[
q_2 = \frac{a-c-q_1}{2}
]
Solve:
[
q_1 = \frac{a-c – \frac{a-c-q_1}{2}}{2}
]
You can solve more quickly by symmetry:
[
q_1=q_2=q \Rightarrow q = \frac{a-c-q}{2}
\Rightarrow 2q = a-c-q
\Rightarrow 3q = a-c
\Rightarrow q = \frac{a-c}{3}
]
Total output:
[
Q=2q=\frac{2(a-c)}{3}
]
Price:
[
p=a-Q=a-\frac{2(a-c)}{3}=\frac{a+2c}{3}
]

Exam payoff: you can compare this with monopoly output ((a-c)/2) (if monopoly has two identical firms? careful: monopoly single firm results differ). Even if not asked to compute, you should comment on output and price effects.

5) Integrative Advanced Topics: Dynamic Choice, Welfare in Strategic Contexts, and Institutional Study Strategy by Course-Level Skills

Dynamic thinking: intertemporal choice at an ECO 301 edge

Some ECO 301 syllabi include an intertemporal extension. Even when it’s not central, the logic of dynamic optimisation shows up in:

• repeated game payoffs
• discounting arguments
• consumer time allocation

Basic intertemporal consumption problem:
[
\max_{c_0,c_1} u(c_0,c_1) \quad \text{s.t.} \quad c_0+\frac{c_1}{1+r}\le w
]
where (r) is interest rate and (w) present value of resources.

For exam purposes, you should be able to interpret:

• budget constraints across time
• effect of interest rate changes
• substitution and income effects intertemporally

Repeated games and discount factor

If oligopoly interaction repeats, cooperation may become stable. In a repeated prisoner’s dilemma, a common threshold condition is framed with discount factor (\delta).

Let:

• Payoff for mutual cooperation: (R)
• Payoff for defection against cooperator: (T)
• Payoff for mutual defection: (P)

A cooperation strategy can be sustained if:
[
R + \delta \frac{R}{1-\delta} \ge T + \delta \frac{P}{1-\delta}
]
which simplifies to a threshold on (\delta) in terms of payoffs.

Exam technique: show the inequality structure even if exact numbers differ.

Welfare in strategic markets: efficiency vs equilibrium

ECO 301 sometimes tests recognition that:

• Nash equilibrium maximises private payoffs, not necessarily total welfare.
• Externalities can exist from firms’ actions (e.g., arms race, pollution under imperfect competition).

You should integrate welfare tools (surplus, DWL) with strategic behaviour:

• monopoly outcome may be welfare inefficient
• cartel may be welfare inefficient compared to competition, depending on market structure and costs
• consumer surplus changes might be asked alongside firm profits

A strong answer distinguishes:

• consumer welfare
• producer welfare
• government revenue
• deadweight loss / efficiency loss

Applied policy and regulation scenarios (South African framing)

South African exam questions sometimes reference regulation and industrial policy contexts. Your job is not to memorise local facts but to apply micro logic to policy instruments. Common policy types in ECO 301-style questions include:

1. Price regulation (e.g., caps; often framed as protecting consumers but may reduce firm incentives).
2. Competition policy logic (mergers can reduce competition; welfare effects depend on cost structure and entry).
3. Taxation for externalities (environmental taxes; “tax equals marginal external cost” principle).
4. Subsidies for positive externalities (education/vaccination-like benefits; should be proportional to marginal external benefit).
5. Public goods provision (cost-sharing and free-rider problem).

Institutional study pack: five-course-level skill clusters (by institution focus)

You requested: “Each cluster must focus on one institution” and “Each title must focus on specific courses offered by an institution.” Since your exact institution list is not provided, the safest approach is to cover five major South African public universities’ typical Economics/Commerce structures using institution-anchored clusters with course-name patterns commonly used in SA programmes (not invented staff names or exact lecturers). If your institution uses different module codes/names, match the skills and model coverage to your syllabus.

Below, each cluster is tied to a South African institution and to ECO 301–level micro skills. Use it as a checklist: whichever institution you’re studying at, follow the corresponding cluster.

Cluster A: University of Johannesburg (UJ) — Microeconomics (ECO 301 equivalent modules) + Applied Welfare & Market Failure Skills

Focus skills likely emphasised in UJ-style Economics/Commerce micro modules:

• Consumer choice derivations with interpretable results
• Welfare calculations (CS/PS and DWL)
• Externality policy using tax/subsidy logic
• Problem sets that combine algebra with graph reasoning

What to practise (minimum set):

1. Derive Marshallian demands for Cobb–Douglas and interpret elasticities.
2. Use Slutsky decomposition to sign-check substitution and income effects.
3. Compute equilibrium before and after a per-unit tax in a linear model.
4. For externalities, identify the social marginal curve and compute efficient quantity (at least conceptually).

Exam technique:

• Show the sequence: set up → solve equilibrium → compute changes in welfare → interpret.
• If asked for DWL, at least articulate the geometric interpretation (triangle areas) and give the formula even if you omit exact decimals.

Cluster B: University of Pretoria (UP) — Advanced Microeconomics (ECO 301 level) + Strategic Interaction (Oligopoly/Game Theory) Skills

Focus skills typically emphasised in UP-like syllabi:

• Nash equilibrium reasoning and elimination of dominated strategies
• Cournot/Stackelberg comparisons
• Welfare critique of monopoly and oligopoly outcomes
• Discount factor logic for repeated interactions

What to practise:

1. Solve 2×2 games: identify best responses and Nash equilibria.
2. Perform IESDS cleanly (show each domination step explicitly).
3. Derive Cournot equilibrium output and price from reaction functions.
4. Compare monopoly vs Cournot vs perfect competition (output and welfare).

Exam technique:

• For every strategic problem, state:
  • What is the strategy space?
  • What is each player’s objective (profit maximisation)?
  • Why is the equilibrium stable (no profitable deviation)?

Even when diagrams are not demanded, write the equilibrium reasoning in words.

Cluster C: University of Cape Town (UCT) — Microeconomics (ECO 301 equivalent) + Welfare, Auctions/Mechanism Intuition, and Rigorous Derivations

Focus skills UCT students often get assessed on:

• Rigor in optimisation and duality logic
• Careful interpretation of compensating/equivalent variation
• Distinguishing efficiency vs fairness
• Understanding how welfare changes with policy

What to practise:

1. Lagrangian derivations: confirm second-order conditions (or justify concavity).
2. Use compensated vs uncompensated demand relationships (Hicks vs Marshall).
3. Compute welfare change under price changes using CV/EV principles.
4. For public goods, apply Samuelson condition conceptually and possibly numerically for simplified cases.

Exam technique:

• When writing welfare, include at least one sentence connecting math to economic meaning:
  • “DWL arises because market quantity differs from social optimum.”
  • “Tax incidence depends on elasticities because marginal responses change quantity.”

Cluster D: Stellenbosch University (SU) — Industrial Organisation Micro (ECO 301 level) + Pricing Strategies and Regulation Skills

Focus skills in SU-like industrial organisation emphasis:

• Monopoly pricing with markup rules
• Price discrimination with different elasticities across groups
• Regulation mechanisms and incentives
• Natural monopoly logic (marginal cost pricing vs average cost recovery)

What to practise:

1. Solve monopoly output by setting (MR=MC).
2. Compute monopoly price and compare with competitive output.
3. For price discrimination, use group elasticities or demands to set separate prices.
4. For regulation, evaluate whether marginal cost pricing covers fixed costs.

Exam technique:

• Always answer “so what?” after computing results:
  • “Marginal cost pricing can require subsidies when fixed costs are high.”
  • “Discrimination can increase output and welfare if it expands trade and doesn’t create excessive distortions.”

Cluster E: North-West University (NWU) — Advanced Micro + Public Economics Interface Skills (Taxes, Externalities, and Market Failure Explanations)

Focus skills likely valued in NWU-type modules:

• Strong conceptual explanations plus workable computations
• Clear policy instrument mapping to the market failure
• Integration of efficiency and distribution in essays

What to practise:

1. Tax incidence: show which side bears the burden with elasticity arguments.
2. Negative externality: show overproduction and welfare loss.
3. Positive externality: show underprovision and welfare gains from subsidies.
4. Public goods: show free-rider issue and Samuelson condition logic.

Exam technique:

• In short answer/essay questions, structure as:
  1. Define problem (market failure)
  2. Show inefficiency (private vs social marginal)
  3. State policy (tax/subsidy/public provision)
  4. Mention limitations (administration, information, political economy)

Exam preparation workflow: a repeatable ECO 301 plan

To maximise marks, follow a disciplined workflow rather than ad hoc studying.

1) Build model templates

Create your own “templates” for:

• Consumer problem (Cobb–Douglas, corner solutions)
• Cost minimisation/MC-AC relationships
• Tax incidence in linear demand/supply
• Externality diagrams and welfare story
• Monopoly (MR=MC)
• Cournot reaction functions
• Nash equilibrium steps

Templates save time and reduce algebra mistakes.

2) Practise under time constraints

For advanced micro, the bottleneck is often not understanding but execution:

• sign errors
• missed constraints
• wrong equilibrium selection

Practise at least:

• 2 questions per day during the final week
• one full derivation problem every alternate day
• one essay or “explain the intuition” question per day

3) Use “marking rubric thinking”

When you write solutions, include:

• a correct setup line
• the correct equilibrium/optimality condition
• algebra
• interpretation and units

If a rubric is unknown, assume those components are required.

4) Common mistakes and how to avoid them

• Budget not binding: in monotonic utility maximisation, budget usually binds.
• Forgetting compensated demand logic: substitution vs income effects.
• Mixing buyer and seller prices under tax: use (p_b=p_s+t).
• Using demand as MR: monopoly requires (MR), not (p).
• Ignoring corner solutions: perfect substitutes/complements change the structure.
• Mistaking Nash stability: equilibrium is “no profitable unilateral deviation.”

A final consolidated checklist (what ECO 301 exams typically assess)

Use this as a last-night checklist before tests.

Consumer choice

• Set up utility maximisation with budget constraint
• Derive Marshallian demand for at least one common utility
• Explain and compute substitution vs income effects (Slutsky logic)
• Interpret signs and elasticities

Firm behaviour

• Cost minimisation logic and marginal cost derivation
• Short-run vs long-run distinctions
• Identify economies of scale implications

Market and welfare

• Equilibrium with linear demand/supply
• Tax incidence reasoning using elasticities
• Externalities: private vs social marginal curves
• DWL and welfare comparisons

Strategic behaviour

• Solve for Nash equilibrium (best responses, dominated strategies)
• Cournot equilibrium via reaction functions
• Monopoly (MR=MC) and welfare critique
• Repeated game intuition via discount factor threshold

Communication

• Clean algebra, correct units, and clear economic interpretation
• Diagrams described in words when not drawn
• Correct policy instrument mapping to market failure

Closing synthesis: how to turn theory into exam marks

ECO 301 advanced microeconomics is not “more chapters” so much as higher-quality problem execution. Examiners reward students who can (1) translate economic statements into mathematical conditions, (2) solve accurately, and (3) interpret results in welfare or strategic terms. The content in this study pack is designed around that: it covers the models you need and the solution choreography you must practise.

If you align your practice with the five institution clusters (UJ, UP, UCT, SU, NWU) and follow the workflow checklist, you’ll develop both conceptual mastery and exam-grade execution—exactly what advanced micro assessments in South Africa typically require.