IBonomics2026-W44
Supply concepts (market supply, shifts vs movements) caused most errors this week
Aggregate quiz activity shows students struggled most with deriving market supply and distinguishing supply shifts from movements driven by expectations.
Published November 8, 2026
Total attempts
63
Unique learners
27
Average score
73.9%
Question accuracy
73.5%
Top problem area
Micro (Units 2.2–2.3): ~57% wrong on key supply items
1. Weekly Overview
Supply-topic errors dominate this week.
Across 63 attempts from 27 learners, accuracy averaged ~73.5%. The weakest items were in Microeconomics (Units 2.2–2.3): deriving market supply and distinguishing supply shifts from movements (several questions ~43% correct). Several items also show long answer times, suggesting hesitation or careful reasoning.
Student takeaway: Prioritise practice on market supply derivation and the difference between movements along supply and supply curve shifts.
2. Key Patterns
Main Insights
Market supply derivation commonly misunderstood
A medium-difficulty item on deriving market supply from individual supply had low accuracy (~42.9% correct, 7 attempts), indicating many learners mix up horizontal summation and other concepts.
Advice: Work through 3–4 worked examples: add individual quantities at given prices, then plot the resulting market curve; practice both numerical tables and graphs.
Expectations and stored output confused with supply shifts
Hard items about stored harvests and seller expectations had low accuracy (~42.9% correct) and long average times, suggesting confusion about whether expectations affect current supply or future supply.
Advice: Clarify the distinction: current supply reflects available quantity for sale now; expectations may change sellers' willingness to sell now versus later — practise scenario questions and label short-run vs future effects.
Demand-driven fashion effects misattributed to supply-side change
When a good becomes fashionable, many learners expected supply-side causes despite unchanged costs and technology; the correct interpretation involves a demand shift raising price and revenue for existing firms.
Advice: Revise demand vs supply shifters and practice tracing price, quantity and producer revenue when demand shifts with supply fixed.
Introductory policy/school-of-thought knowledge needs attention
A question on Milton Friedman and monetarism had low accuracy (25% correct, 4 attempts), suggesting some gaps in basic economic schools and policy views.
Advice: Review key characteristics of major schools (classical, Keynesian, monetarist) and their policy prescriptions; use short comparison tables to memorise hallmark ideas.
3. Revision Plan
Priority Areas
Deriving market supply (horizontal summation) · 2.2
Low accuracy on direct derivation items (≈43% correct).
Action: Practice 4 numerical examples converting individual supply schedules to a market supply curve and sketch corresponding graphs.
Shifts vs movements in supply (expectations & stored output) · 2.2
Confusion where expectations and storage change sellers' timing of sales.
Action: Work through scenario questions that ask whether a change affects current supply, future supply, or price expectations; write brief explanations for each case.
Demand-led changes and firm revenue · 2.3
Errors interpreting higher revenue after a demand shift when costs and sellers are unchanged.
Action: Practice AD/AS and supply-demand diagrams showing how a demand shift affects price, quantity and producer revenue; calculate simple revenue changes.
Schools of economic thought (monetarism) · 1.2
Key definitions and policy positions showed low accuracy.
Action: Create a one-page comparison (Monetarist vs Keynesian vs Classical) with core claims and policy prescriptions; self-test with 5 flash questions.
4. Question Evidence
Featured Questions
Most Wrong Questions
| Question | Topic | Unit | Attempts | Correct | Wrong | Avg Time |
|---|---|---|---|---|---|---|
| In Ibonomica, the dried-fig harvest is complete and all output is already stored. Sellers expect a much higher price next month. What happens to current supply, and why? | Microeconomics | 2.2 | 7 | 42.9% | 57.1% | 34.1 s |
| How is market supply derived from individual supply? | Microeconomics | 2.2 | 7 | 42.9% | 57.1% | 12.0 s |
| In Ibonomica, decorative plant pots become fashionable. Costs, technology and the number of sellers stay unchanged, yet existing firms make more over the following weeks. Why? | Microeconomics | 2.3 | 7 | 42.9% | 57.1% | 41.2 s |
| Milton Friedman and the monetarist school emphasized: | Introduction to Economics | 1.2 | 4 | 25.0% | 75.0% | 29.3 s |
| A new production method reduces the cost of making insulated flasks in Ibonomica. With demand unchanged, what happens to consumer surplus? | Microeconomics | 2.3 | 8 | 62.5% | 37.5% | 54.0 s |
Most Correct Questions
| Question | Topic | Unit | Attempts | Correct | Wrong | Avg Time |
|---|---|---|---|---|---|---|
| What happens to the demand curve when there is an increase in consumer income for a normal good? | Microeconomics | 2.1 | 8 | 100.0% | 0.0% | 16.4 s |
| How is market demand derived from individual demand? | Microeconomics | 2.1 | 9 | 88.9% | 11.1% | 23.9 s |
| Which of the following is a non-price determinant of supply? | Microeconomics | 2.2 | 10 | 80.0% | 20.0% | 25.2 s |
| According to the law of demand, what happens when the price of a good increases, assuming ceteris paribus? | Microeconomics | 2.1 | 7 | 100.0% | 0.0% | 44.1 s |
| What does the law of supply state? | Microeconomics | 2.2 | 7 | 100.0% | 0.0% | 7.6 s |
Most Time Spent Questions
| Question | Topic | Unit | Attempts | Correct | Wrong | Avg Time |
|---|---|---|---|---|---|---|
| What does a supply curve represent in economics? | microeconomics | 2.2 | 3 | 100.0% | 0.0% | 47.6 min |
| If the number of firms in a market increases, what happens to the market supply? | Microeconomics | 2.2 | 6 | 66.7% | 33.3% | 10.6 min |
| What does effective demand refer to in economics? | microeconomics | 2.1 | 3 | 100.0% | 0.0% | 10.3 min |
| What is meant by contraction in supply? | microeconomics | 2.2 | 3 | 33.3% | 66.7% | 7.9 min |
| The central bank of Ibonomica announces a significant cut in its policy interest rate to combat a recession and high unemployment. In the AD–SRAS diagram, which curve is most likely to shift in the short run, and in which direction? | Macroeconomics | 3.5 | 3 | 100.0% | 0.0% | 5.0 min |
5. Conclusion
Targeted microeconomics practice will pay off
Focus short weekly sessions on market-supply derivations and distinguishing supply shifts from movements (use diagrams and numerical tables). Add one quick review of economic schools to strengthen foundational vocabulary.
Note: This weekly report is automatically generated and may contain mistakes. Always double-check key points before using them for revision.
This report summarises anonymized aggregate quiz activity and question-level statistics only; it does not include or imply any individual student data.