2026-W16

Combined diagram shifts caused most errors; strong basics on substitution and interest-rate effects

This week students averaged 79% but struggled with multi-effect diagram questions (supply/demand, expectations, remittances and AD–SRAS shifts).

Published April 26, 2026

Total attempts

151

Unique students

Average score

79%

Question accuracy

78.7%

Avg time per question

29.1 s

1. Weekly Overview

Multi-shift diagrams are the main weakness this week.

Aggregate results: 151 attempts by 35 students, average score 79% and overall question accuracy ~78.7%. High accuracy appeared on single-effect substitution/complement and basic interest-rate impact questions, while multi-effect comparative-static and cross-border flow diagrams produced the most errors and longer working times.

Student takeaway: Focus your revision on drawing and labelling combined shift diagrams (Micro 2.1–2.2), AD–SRAS policy responses (Macro 3.5), and mapping remittance flows (Global 4.5).

2. Key Patterns

Main Insights

Most errors on combined comparative-static diagrams

Questions that required drawing multiple simultaneous shifts (policy + expectations or subsidy + expectations) had low correct rates and above-average times, indicating difficulty integrating effects step by step.

Advice: When a scenario lists multiple shocks, trace each effect separately on the same axes, label which curve shifts first, then show the net outcome; practice 3-step annotations on past-paper diagram questions.

Confusion with international remittance flows on diagrams

The lowest correct rate occurred for a remittance-flow diagram in Global Economy (unit 4.5), suggesting students struggle to represent which country records credited vs debited flows or how to show bilateral transfers.

Advice: Review how remittances appear in balance-of-payments or flow diagrams: practice drawing arrows with clear origin/destination labels and annotating which account (current account/financial account) records the flow.

Strength: clear grasp of substitution/complement effects and basic interest-rate impacts

Perfect or very high accuracy on questions about substitutes/complements and the economy-wide effects of rising interest rates shows good command of single-effect reasoning.

Advice: Keep practising single-shock reasoning to maintain this strength, then extend the same stepwise logic when combining shocks.

3. Revision Plan

Priority Areas

Multi-effect supply and demand diagrams · 2.1–2.2

High error rates on questions combining subsidies, expectations and supply/demand shifts.

Action: Practice 10 past-paper diagram questions showing two simultaneous shocks; annotate each step and check net shifts.

AD–SRAS policy responses (monetary tightening) · 3.5

Low accuracy on which AD/AS curve moves after interest-rate changes and signalling.

Action: Work through labeled AD–SRAS examples: show short-run vs long-run effects and write one-sentence explanations for each shift.

Remittances and balance-of-payments representation · 4.5

Very low correct rate on remittance-flow diagrams across countries.

Action: Draw incoming/outgoing remittance arrows for both countries, label credits/debits, and complete 5 sample transactions to build fluency.

4. Question Evidence

Featured Questions

Most Wrong Questions

Question	Topic	Unit	Attempts	Correct	Wrong	Avg Time
More Mexican workers in the USA send money home while more US retirees in Mexico send pension income back to the USA. How would you show these remittance flows on the diagram?	Global Economy	4.5	8	12.5%	0.0%	—
Facing persistent demand-pull inflation, the Bank of England decides to increase its base rate and signals further tightening. According to the AD–SRAS model, which curve shifts as a result of this policy decision, and in which direction?	Macroeconomics	3.5	7	14.3%	0.0%	—
In a single diagram for solar panels, show the effects of a government production subsidy and rising expectations that future electricity prices will be much higher.	Microeconomics	2.2	10	20.0%	0.0%	—

Most Correct Questions

Question	Topic	Unit	Attempts	Correct	Wrong	Avg Time
Laptops and tablets are substitutes, while laptops and laptop cases are complements. A large fall in the price of tablets occurs at the same time as a small fall in the price of laptop cases. If the substitution effect from tablets is stronger than the complement effect from cheaper laptop cases, what happens to the demand for laptops?	Microeconomics	2.1	12	100.0%	0.0%	—
How is the economy affected when interest rates rise significantly?	Macroeconomics	3.5	12	100.0%	0.0%	—
A severe drought hits a major rice-growing region, show what happens to the market supply of rice?	Microeconomics	2.2	11	100.0%	0.0%	—

Most Time Spent Questions

Question	Topic	Unit	Attempts	Correct	Wrong	Avg Time
Consider game consoles (e.g., PS5) and high-end gaming PCs as substitutes, and PS5 consoles and PS5 games as complements. The price of gaming PCs rises significantly, while the average price of PS5 games falls slightly. Assuming both effects work in the same direction, what happens to the demand for PS5 consoles?	Microeconomics	2.1	8	62.5%	0.0%	5.0 min
Why might interventionist supply-side policies be criticized?	Macroeconomics	3.7	4	75.0%	0.0%	3.4 min
The US Federal Reserve (Fed) sharply raises interest rates to reduce inflation that is well above target. In the AD–SRAS framework, which curve is primarily affected in the short run, and how does it move?	Macroeconomics	3.5	11	100.0%	0.0%	1.8 min

5. Conclusion

Targeted diagram practice

Spend short, focused sessions drawing multi-shock diagrams and labelling each step; combine that with 5 remittance/balance-of-payments sketches and 5 AD–SRAS policy traces this week to convert understanding into fluent exam technique.

Note: This weekly report is automatically generated and may contain mistakes. Always double-check key points before using them for revision.

This report is based on anonymized aggregate quiz activity from the cited weekly summary and does not include or imply any individual student data.