2026-W13

Supply shifts and producer expectations are the week's biggest difficulty

Students did well on standard supply changes (taxes, input costs, joint supply) but struggled when expectations or complex multi-shift diagrams affect current supply.

Published April 5, 2026

Total attempts

110

Active learners

Average score

80.7%

Question accuracy

79.3%

Interactive quizzes attempted

1. Weekly Overview

Expectations and multi-shift diagrams caused most errors this week.

Aggregate quiz activity (110 attempts across 26 learners) shows good performance on routine supply topics (subsidies, taxes, input-price effects, joint supply) but persistent errors where firms' expectations or simultaneous forces change current supply. Several macro questions on technology and aggregate supply also had very low accuracy.

Student takeaway: Focus revision on how producer expectations and technology shocks shift current supply curves and practise single diagrams that combine multiple simultaneous changes.

2. Key Patterns

Main Insights

Biggest weakness: supply responses to producer expectations

Multiple high-attempt questions about how expectations of future prices affect current supply had very low correct rates (several ~0–6%). This is the strongest signal of a conceptual gap.

Advice: Revise the logic: when producers expect lower future prices, they may increase current supply (sell now) or reduce production depending on inventories and perishability—practice categorising scenarios and drawing the immediate supply shift.

Clear strength: standard supply mechanisms

Students reliably answered questions on joint supply, tax removal, and input-cost reductions with high accuracy, showing solid grasp of basic supply shifts.

Advice: Keep using short, labelled diagrams for tax/subsidy and input cost changes; use these strengths to anchor more complex multi-shift problems.

Time-on-question flags complexity, not always lack of knowledge

Several correctly answered items show unusually long average times, indicating careful reasoning on multi-factor diagrams; other long-time items were answered incorrectly, suggesting hesitation or uncertainty under complexity.

Advice: Practice timed diagram questions to reduce hesitation: aim to identify affected curves and direction of shift within the first 60–90 seconds, then label and explain.

3. Revision Plan

Priority Areas

Producer expectations and current supply decisions · 2.2

Multiple low-accuracy items show confusion about how anticipated future prices change present supply.

Action: Work through 6–8 past questions that explicitly state producers' expectations; for each, write one-sentence reasoning and draw a quick supply diagram.

Combined demand and supply shifts in one diagram · 2.2

Students struggled with multi-factor diagrams where both demand and supply or multiple supply influences occur simultaneously.

Action: Practice 10 timed combo-diagram problems (90–120s each): list each force, pick curve(s) affected, show direction, then state net price and quantity effect.

Technology shocks and aggregate supply (three-curve framework) · 3.2

A macro question on technology removal had 0% correct rate, indicating uncertainty about which aggregate-supply curve is most directly affected.

Action: Review AD/SRAS/LRAS definitions and do 5 examples of positive and negative technology shocks, indicating short- and long-run shifts and why.

Applying joint-supply logic · 2.2

While accuracy is high, long response times suggest students can answer but take long to structure explanations.

Action: Summarise joint-supply cases in 1–2 sentences and practice answering 5 quick-response questions (<=60s each).

4. Question Evidence

Featured Questions

Most Wrong Questions

Question	Topic	Unit	Attempts	Correct	Wrong	Avg Time
In a single diagram for IB Economics revision courses, show what happens when more EdTech firms enter the market while a new, very effective free online resource reduces students' willingness to pay for paid courses.	Microeconomics	2.2	18	0.0%	100.0%	22.8 s
Farmers expect the price of wheat to fall significantly in the near future. What is likely to happen to the current market supply of wheat?	Microeconomics	2.2	18	5.6%	94.4%	18.4 s
If smartphone makers expect a recession that will lower future phone prices, what is likely to happen to the current supply of smartphones?	Microeconomics	2.2	28	46.4%	53.6%	28.6 s
A new AI-powered logistics system makes it cheaper and faster to deliver online grocery orders; what happens to the supply of online groceries?	Microeconomics	2.2	12	0.0%	100.0%	12.0 s
Due to an AI takeover that ends in all technology being wiped out, many firms end up operating with outdated machinery and inefficient production methods. In the three-curve diagram, which curve is most directly influenced and in which direction does it shift?	Macroeconomics	3.2	7	0.0%	100.0%	33.2 s

Most Correct Questions

Question	Topic	Unit	Attempts	Correct	Wrong	Avg Time
Demand for beef falls, leading to a lower price and reduced production of beef. Beef and leather are jointly supplied from the same cows. What happens to the market supply of leather?	Microeconomics	2.2	28	100.0%	0.0%	8.9 min
What are the effects on demand and supply from a government subsidy?	Microeconomics	2.2	34	79.4%	20.6%	49.5 s
The government removes a indirect tax on fortnite skins. What happens to the supply curve of fortnite skins?	Microeconomics	2.2	25	100.0%	0.0%	12.0 s
If the price of microchips used in laptop production falls due to cheaper imports, what happens to the market supply of laptops?	Microeconomics	2.2	22	100.0%	0.0%	20.1 s
Several new firms enter the market for online streaming services. What happens to the overall market supply of streaming services?	Microeconomics	2.2	22	100.0%	0.0%	10.2 s

Most Time Spent Questions

Question	Topic	Unit	Attempts	Correct	Wrong	Avg Time
Demand for beef falls, leading to a lower price and reduced production of beef. Beef and leather are jointly supplied from the same cows. What happens to the market supply of leather?	Microeconomics	2.2	28	100.0%	0.0%	8.9 min
A government decides to cut or remove existing subsidies for public universities. What happens to the market supply of university places in the short run?	Microeconomics	2.2	18	100.0%	0.0%	6.1 min
In a single diagram for electric cars, show the impact of falling battery costs and rising incomes that make more households able to afford EVs.	Microeconomics	2.2	20	65.0%	35.0%	2.4 min
In a single diagram for petrol, show the impact of a new indirect carbon tax on petrol and a simultaneous fall in household incomes during a recession.	Microeconomics	2.2	14	100.0%	0.0%	2.0 min
The price of apples rises while the price of oranges remains unchanged. Many farmers can switch between producing apples and oranges using the same land. What happens to the market supply of oranges?	Microeconomics	2.2	12	100.0%	0.0%	1.8 min

5. Conclusion

Next steps this week

Target short practice sets on expectations and combined-shift diagrams, review AD/SRAS/LRAS responses to technology shocks, and time yourself when drawing diagrams to build speed and clarity.

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 patterns; it does not include or imply any individual student data.