Executive Examiner Verdict
The October 2025 series presents a balanced but rigorous challenge across both AS (Units 1 and 2) and AL (Units 3 and 4) papers. The papers heavily reward students who master precise diagrammatic mechanics and maintain multi-stage chains of economic reasoning. Candidates often lose simple marks by failing to customize diagrams to specific scenarios, such as shifting both supply and demand for rice in Unit 1, or accurately showing loss-minimization in Unit 3.
Where the Marks Are Won or Lost
A key differentiator in this series is the quality of case study integration in Section D. In Unit 2 and Unit 4, the mark schemes strictly enforce a cap at Level 3 (maximum 9 out of 12 marks for KAA) if there is no explicit country context. For Unit 3, the exact representation of short-run losses where average cost is shifted entirely above average revenue is a frequent separator between Grade A/B candidates and lower tiers. Quantitative questions, including the calculation of the multiplier effects (where \( \text{Multiplier} = \frac{1}{1 - \text{MPC}} = 2.5 \)) and index numbers, remain reliable sources of high-margin marks for well-prepared students.
Examiner Pitfalls to Avoid
- Vague Macro Labels: In Unit 2 aggregate supply questions, candidates frequently label the vertical axis as "Price" instead of "Average Price Level" (APL), and the horizontal axis as "Quantity" instead of "Real Output" or "Real GDP". This oversight prevents candidates from scoring full diagrammatic marks.
- Welfare Loss Errors: In Unit 1 negative externality diagrams, the welfare loss triangle must point toward the socially optimum output \( Q_{so} \). Too many students draw it pointing outward or misalign the marginal social cost (MSC) line.
- Arbitrage Ignored in Price Discrimination: In Unit 3 essays, students often evaluate the benefits of price discrimination without analyzing the essential pre-conditions, such as the prevention of market arbitrage.
Strategic Advice & Prediction
For upcoming series, candidates should prioritize practicing asymmetric information and monopolistic competition long-run transitions, which were less prominent in this series. In macroeconomics, look out for overdue questions on the J-Curve effect and financial market regulation. Focus revision on linking macroeconomic policies directly to microeconomic incentives to maximize synoptic marks.