Assam ASSEB HS Class 11-12 Economics common mistakes
Assam ASSEB HS Class 11-12 Economics · Understand the traps and how to avoid them.
When computing national income by the value-added (product) method, the candidate adds the full market value of every firm's output instead of summing only value added, so intermediate goods are counted twice and the total is inflated.
Candidates memorise 'sum of all production' without internalising the double-counting problem; the distinction between intermediate and final goods feels abstract, and the exam often presents a small table of firms where the trap is easy to miss under time pressure.
What to do instead
Before adding anything, write the rule at the top of the answer: sum of value added = sum of (sales + change in stock) − intermediate consumption, or equivalently sum of factor incomes. Practise with 3–5 firm tables, computing both GVA at market price and the income-method total, and check the two agree. Explicitly label each row 'intermediate' or 'final' before summing.
The candidate treats every increase in nominal (current-price) national income as real growth, or deflates using the wrong base year, and reports a real GDP figure that ignores price change.
Students conflate the two aggregates because both are called 'national income' in textbooks, and they rarely practise the GDP deflator arithmetic in reverse (finding real from nominal).
What to do instead
Fix the identity Real GDP = (Nominal GDP / GDP deflator) × 100 in memory and always state which price basis the question uses. Solve one numerical each on nominal-to-real conversion and one on real-to-nominal, and write a one-line sentence interpreting the result ('output rose X% because prices rose Y%').
While answering elasticity questions, the candidate computes price elasticity of demand as a simple ratio of absolute changes (ΔQ/ΔP) rather than percentage changes, and reports a value greater than one for an inelastic good.
The percentage-change formula is introduced alongside percentage-change questions in statistics, and candidates under exam pressure default to the simpler subtraction they used in earlier classes; they also forget to take the absolute value.
What to do instead
Write the formula with the percentage signs visible: Ed = (ΔQ/Q × 100) ÷ (ΔP/P × 100), and note that the sign is dropped for price elasticity of demand. Do a quick sanity check on every answer: necessities should give Ed < 1, luxuries Ed > 1, and a perfectly vertical demand curve must give 0, not infinity.
The candidate confuses a movement along the demand curve (change in quantity demanded caused by own-price change) with a shift of the demand curve (change in demand caused by income, tastes, prices of related goods), and labels a price change as a shift.
Both cases produce a new point on a graph, and the terminology 'increase in demand' versus 'increase in quantity demanded' is easily swapped. Textbooks present shifts and movements side by side, so the visual memory blurs.
What to do instead
Adopt a two-question test before drawing: (1) Is the change caused by the good's own price? If yes, it is a movement along the curve. (2) If not, name the determinant and shift the curve left or right. Practise by writing the determinant next to each scenario before touching the graph, and always label the axes and the direction of the arrow.
In supply and producer-behaviour numericals, the candidate mixes up total product, average product and marginal product, or states that the law of variable proportions applies in the long run when all factors can change.
The three product curves are drawn together and their relationships (MP cuts AP at AP's maximum) are memorised as shapes rather than derived; the short-run/long-run distinction is treated as a definition to recite, not a condition to apply.
What to do instead
Reconstruct the table from a single input column: TP by cumulative addition, MP as the increment, AP as TP/L. Then verify the three rules numerically (MP > AP means AP rising; MP = AP at AP maximum; MP < 0 means TP falling). For every question, first ask 'is any factor fixed?' - if none is fixed, the law of variable proportions does not apply.
When identifying market forms, the candidate labels any market with many sellers as perfect competition, ignoring the other conditions (homogeneous product, free entry and exit, perfect knowledge, no transport cost), and then applies the price-taker assumption to a monopolistically competitive firm.
Textbook definitions list four or five conditions, but exam questions often give a short scenario naming only one feature; candidates latch onto the salient number of firms and skip the rest.
What to do instead
Keep a five-column checklist (number of sellers, product differentiation, entry barriers, price control, knowledge) and tick each column against the scenario before naming the market. Add a one-line justification in the answer, since examiners award marks for the reason, not just the label.
The candidate answers money-multiplier and credit-creation questions by treating the whole deposit as new credit, or computes the multiplier as 1/rr but then applies it to total deposits rather than to initial excess reserves, producing a money supply figure far too large.
The process is taught as a sequence of rounds, and students collapse it into a single step without tracking which base the multiplier applies to; the distinction between required reserves and excess reserves is glossed over.
What to do instead
Work the process in a small table: round, new deposit, required reserve, new loan. Then state the formula Total deposit creation = Initial deposit × (1/LLR) and note that if banks hold excess reserves, the effective reserve ratio is larger and the multiplier smaller. Always identify the initial injection explicitly before multiplying.
In income-determination numericals, the candidate confuses the investment multiplier with the government-expenditure multiplier or forgets that the tax multiplier is negative, and then reports a change in equilibrium income with the wrong sign or magnitude.
All three multipliers share the 1/(1−MPC) structure, and students memorise one formula and apply it indiscriminately; the balanced-budget multiplier result (equal to 1) is often memorised without understanding why.
What to do instead
Write the four multipliers side by side with their signs: investment and government spending = 1/(1−MPC); tax = −MPC/(1−MPC); transfer = MPC/(1−MPC); balanced budget = 1. Before substituting, identify which instrument changed and whether it raises or lowers aggregate demand, then check the sign of the answer against intuition.
On balance-of-payments questions, the candidate treats the current account and capital account as interchangeable, or records a foreign loan received as a credit on the current account, and concludes that a current account deficit is necessarily bad.
Both accounts use credit/debit language and the 'balance' terminology suggests symmetry; textbook treatment of autonomous versus accommodating transactions is brief, so the accounting logic is not internalised.
What to do instead
Draw a two-row table (current, capital) with credit and debit columns and place each transaction by asking 'is this a flow of goods, services or income (current) or a flow of financial claims (capital)?'. Remember the BoP always balances overall, so a current account deficit must be matched by a capital account surplus. Explain the surplus/deficit interpretation in one sentence rather than judging it.
In statistics questions the candidate computes the arithmetic mean for grouped data using class midpoints without checking whether the classes are continuous, or computes correlation and then interprets r = −0.9 as a weak relationship because the sign is negative.
The mechanics of the assumed-mean and step-deviation methods are drilled, but the interpretive meaning of the coefficient and the preliminary step of making classes continuous are treated as optional; students also confuse the sign with the strength.
What to do instead
Before any grouped-data calculation, adjust class limits to class boundaries (subtract 0.5 from lower limits, add 0.5 to upper limits) and state it. For correlation, always write 'strength = |r|, direction = sign' and give both in the answer: r = −0.9 means a strong negative linear relationship. Add a one-line interpretation after every coefficient so the habit becomes automatic.