Intro Economics

What this covers

• Reading and shifting supply and demand curves: distinguishing a change in quantity demanded from a change in demand, and predicting equilibrium price and quantity after a shift
• Elasticity calculations (price, income, cross-price) and using elasticity to explain revenue changes and tax incidence
• Marginal thinking: opportunity cost, sunk costs, marginal cost versus marginal revenue, and the firm's shutdown and profit-maximising rules
• Market structures compared — perfect competition, monopoly, monopolistic competition, oligopoly — and the efficiency and deadweight-loss arguments about each
• Macro measurement: nominal versus real GDP, CPI and inflation rates, the unemployment rate and what it leaves out
• Fiscal and monetary policy in the AD-AS and loanable funds frameworks, including multipliers, crowding out, and central bank interest rate tools

Where learners get stuck

Shifting the demand curve when the price of the good itself changes

In everyday language 'demand went down because it got expensive' is perfectly sensible. The model reserves shifts for the non-price determinants only — income, tastes, related goods, expectations, buyers — so students have to unlearn a normal way of speaking and check which variable is on the axis.

Treating absolute advantage and comparative advantage as the same idea

Comparative advantage requires comparing opportunity cost ratios, not output levels, and the arithmetic gives a counterintuitive result: a country worse at producing everything still gains from trade. Students often compute output per worker, see one column dominate, and stop there.

Adding sunk costs into a decision, or using average cost where marginal cost is required

Accounting habits and intuition both say 'count what you spent.' Economic decision rules deliberately ignore unrecoverable costs and compare only the next unit's cost and benefit, which is why the shutdown rule uses average variable cost while the exit rule uses average total cost — a distinction that is easy to memorise wrongly.

Confusing nominal and real values, especially with interest rates and GDP

Both are reported in currency units, so the difference is invisible unless you deliberately deflate. The Fisher relationship and real GDP calculations both require holding prices fixed, and students often skip the base-year step.

What a session looks like

A typical session starts with you stating the problem or chapter you are working on, then reasoning through it aloud while the tutor asks where each curve moves and why. Because graphs are central, you will often be asked to describe what you have drawn — axes, initial equilibrium, direction of shift, new equilibrium — which surfaces errors quickly. Numerical work (elasticity, multipliers, real GDP, per-unit tax burdens) is checked step by step, and definitions are pushed toward application: not 'what is deadweight loss' but 'where is it on this diagram and who bears it.'

Helpful to know first

• Comfort with linear equations, slopes, and reading a two-variable graph
• Percentage change and ratio calculations without a calculator crutch
• No prior economics coursework assumed; most intro sequences start from scratch

Questions

Should I take microeconomics or macroeconomics first?

Most programmes sequence micro first because supply and demand, marginal analysis, and market efficiency reappear inside macro models. If your school lets you choose, micro first tends to make aggregate supply and demand feel more familiar. Either order works for tutoring — sessions follow your syllabus.

How much maths is in an intro economics course?

Non-calculus intro sections stay with linear functions, slopes, percentage changes, and simple algebra: solving for equilibrium, computing elasticity, applying a multiplier. Calculus-based sections add derivatives for marginal cost and utility. Check your course code, since the same catalogue title can mean either.

Why do I understand the lecture but lose marks on the graph questions?

Recognising a diagram is different from producing one under time pressure. Exam graphing needs a fixed routine — label both axes, mark the starting equilibrium, shift one curve at a time, then read off the new price and quantity — and that routine is built by drawing repeatedly while explaining each step, which is what practice sessions focus on.

Can this help with problem sets and essay questions, or only test review?

Both. Problem sets are worked through with you rather than answered for you, and short-answer or essay prompts are practised by outlining the model, the prediction, and the assumption that drives it — the structure most intro rubrics reward.