MATSEC SEC Economics common mistakes
MATSEC SEC Economics · Understand the traps and how to avoid them.
Defining a term by restating it in other words (e.g. 'demand is how much people want a good') instead of giving the economic condition, such as willingness and ability to buy at each price over a period, ceteris paribus.
Candidates memorise a one-line gloss and never learn the qualifying conditions, so under time pressure they write the everyday meaning of the word rather than the syllabus definition.
What to do instead
For each key term build a three-part definition card: the concept, its conditions (ceteris paribus, time period, willingness and ability, effective demand), and one example. Test yourself by covering the card and saying all three parts aloud.
Describing a movement along a demand or supply curve as a shift (or vice versa), so a price change is said to 'shift demand' and a change in income is said to 'move along the curve'.
The two changes look similar in a diagram and candidates learn 'price affects demand' without distinguishing a change in the quantity demanded from a change in demand itself.
What to do instead
Draw one diagram with a curve and label two arrows: along the curve for price changes, whole-curve shift for non-price determinants. List the non-price determinants (income, tastes, prices of related goods, expectations, number of buyers) and practise classifying ten short scenarios into 'along' or 'shift'.
Drawing diagrams freehand with unlabelled axes, no curve labels, no equilibrium price and quantity marked, and no arrows showing the direction of change, then expecting method marks.
Candidates treat diagrams as decoration rather than as an answer, and exam pressure leads them to sketch quickly and move on to prose.
What to do instead
Adopt a fixed drawing routine: label both axes with variable and units, label every curve, mark original equilibrium, show the shift with an arrow, mark the new equilibrium, and annotate the change in price and quantity. Rehearse the routine on five standard diagrams until it is automatic.
Calculating price elasticity of demand as the absolute change in quantity divided by the absolute change in price, or forgetting to take the absolute value and then mislabelling a normal good as elastic.
The formula is learned as 'change over change' without the percentage step, and candidates are unsure what the resulting number means.
What to do instead
Always write the formula as percentage change in quantity demanded over percentage change in price, show the percentage step explicitly, and state the interpretation in words (e.g. 'demand is price elastic because the value exceeds one, so a price rise reduces total revenue'). Practise with numbers where price and quantity both change.
Treating fixed costs as costs that never change and variable costs as costs that always rise proportionally, so a firm's total cost curve is drawn as a straight line from the origin or fixed costs are said to disappear in the long run.
Short-run and long-run distinctions are learned as vocabulary rather than as statements about which inputs can vary, so the cost curves are drawn from intuition rather than from the definition.
What to do instead
Anchor the definitions: in the short run at least one factor is fixed, so fixed costs exist and average fixed cost falls as output rises; in the long run all factors vary, so all costs are variable. Draw total fixed, total variable and total cost on one diagram and explain why the total cost curve starts above the origin.
Describing monopoly as 'a firm that is the only seller' and stopping there, without stating barriers to entry, the absence of close substitutes, price-making power, or the possibility of natural monopoly.
Candidates learn a label rather than a market-structure checklist, so they cannot compare monopoly with perfect competition or oligopoly.
What to do instead
Build a comparison table with rows for number of firms, nature of product, barriers to entry, price control, knowledge, and examples, and fill it for perfect competition, monopolistic competition, oligopoly and monopoly. Learn the table, then answer structure questions from it.
Confusing GDP with GNP, or treating GDP as a measure of living standards without mentioning real versus nominal values, population, income distribution, unpaid work and environmental costs.
The national income aggregates are learned as acronyms, and evaluation of GDP as a welfare measure is skipped because candidates think the definition is enough.
What to do instead
Write a one-page comparison of GDP, GNP, nominal and real, and per capita, with the formula for each. Then prepare four evaluation points on GDP as a living-standards measure with a one-sentence example for each, so evaluation marks are earned rather than improvised.
Describing inflation as 'prices going up' without distinguishing demand-pull from cost-push, and stating that inflation always harms everyone without separating savers, borrowers, exporters, pensioners and wage earners.
Candidates learn a single cause and a single consequence, so they cannot reach the analysis and evaluation marks that require differentiated effects.
What to do instead
Make a two-column cause sheet (demand-pull, cost-push, imported, monetary) and a winners-and-losers table for inflation and deflation. For each group write one line explaining the mechanism, e.g. 'borrowers gain because the real value of debt falls'.
Using vague quantifiers and unsupported assertions in essay answers ('many people', 'it is very bad for the economy', 'the government should just spend more') instead of chains of reasoning, data where available, and a judgement.
Candidates run out of things to say and pad with generalities, and they have not been taught that analysis means explaining each link in a causal chain.
What to do instead
Practise the 'because, therefore, which means' chain: a change, its immediate effect, the transmission mechanism, and the final effect on a named variable. End every essay with an explicit judgement that weighs two competing effects and states a condition under which the conclusion would change.
Ignoring the command word: writing an explanation when asked to discuss, listing points when asked to evaluate, or failing to use the data given in a stimulus question.
Under time pressure candidates read the topic and not the instruction, and they have not internalised what each command word demands.
What to do instead
Underline the command word before planning. Learn a short rule for each: describe means state features; explain means give reasons; discuss means both sides plus a conclusion; evaluate means weigh and judge. For data questions, quote at least two specific figures from the stimulus and use them in the argument.