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Economics lecture notes: models, graphs and quizzes
Turn economics lecture recordings and slides into summaries, quizzes and flashcards that keep models, graphs and calculation steps. See an elasticity example.
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The challenge in economics: assumptions, graphs and calculations
In economics a result is hard to separate from the assumption and graph behind it. The “all else equal” assumption, the difference between a movement along a curve and a shift of the curve, and the method used in a calculation can easily disappear from a short summary. A lecturer drawing a graph on the board may not describe every step aloud.
With LectureSift you can upload a lecture video or audio recording and create a transcript, a detailed summary, a quiz with explained answers and flashcards. Slides, problem sets or textbook chapters are processed as a separate document pack. For videos that contain a presentation, selecting slide images can help you see the written form of graphs in the pack.
From lecture recording to graph and calculation practice in three steps
Separate the recording and the slides.
Turn the lecture recording into one pack and the slides or problem set into a separate document pack. For long lectures, add several recordings in the order they were taught.
Put every graph into words.
For each graph in the summary, write the axes, the curves and what changes in your own sentence: is it a movement along the curve or a shift of the curve?
Solve with the method stated.
When you answer a numerical quiz question, note which formula you used. If your lecturer expects the midpoint method, a simple percentage change can give a different answer.
Example output structure: price elasticity of demand
This section is an example. It was written for teaching purposes to show the structure of a study pack that could be created from a microeconomics lecture. It is not the output of a real lecture, student or upload; the sections of your own pack depend on the lecture content and the settings you choose.
Summary: key ideas
- Definition: The price elasticity of demand is the percentage change in quantity demanded divided by the percentage change in price. Because of the law of demand the sign is usually negative; interpretation uses the absolute value.
- Classification: |E| > 1 elastic, |E| = 1 unit elastic, |E| < 1 inelastic demand.
- Midpoint method: Percentage changes are calculated relative to the average of the starting and ending values, so a price rise and a price fall give the same result.
- Total revenue: If demand is elastic, a price rise reduces total revenue; if it is inelastic, a price rise increases it.
- Assumption: The calculation holds while other factors, such as income and the prices of other goods, stay constant.
| Step | Simple percentage change | Midpoint method |
|---|---|---|
| Change in quantity | (80 − 100) ÷ 100 = −20% | (80 − 100) ÷ 90 ≈ −22.2% |
| Change in price | (12 − 10) ÷ 10 = 20% | (12 − 10) ÷ 11 ≈ 18.2% |
| Elasticity | −20 ÷ 20 = −1 (unit elastic) | −22.2 ÷ 18.2 ≈ −1.22 (elastic) |
| Total revenue | 10 × 100 = 1,000 → 12 × 80 = 960 | The fall in revenue is consistent with elastic demand |
Quiz question
When the price rises from 10 to 12, quantity demanded falls from 100 to 80. Using the midpoint method, how would you describe demand over this range? A) Inelastic · B) Unit elastic · C) Elastic · D) Perfectly elastic
Show the answer and explanation
C) Elastic, with an absolute value of about 1.22. The percentage fall in quantity (about 22.2%) is larger than the percentage rise in price (about 18.2%). The fall in total revenue from 1,000 to 960 is consistent with this result. Option B is what you get with simple percentage changes from the starting values, which is why it matters to note the method your course expects.
Flashcards
If demand is elastic, how does a price rise affect total revenue?
It reduces it, because the percentage fall in quantity is larger than the percentage rise in price.
What is the difference between a movement along a demand curve and a shift?
A change in the good's own price moves you along the curve and changes quantity demanded. A change in another factor, such as income or tastes, shifts the curve and changes demand.
Flashcards help you recall definitions and directions. To check that you know the calculation, change the price or quantity, apply both methods again and run the revenue check.
Tips for economics students
- Add the assumption to the summary. If assumptions such as “all else equal” are missing from the summary, add them; the result often depends on them.
- Check graphs separately. A graph drawn on the board and not described aloud will not appear in the transcript. Select slide images for a video with a presentation, or draw the graph in your own notes.
- Note data with its date. Inflation, growth or interest rates mentioned in a lecture belong to that period. Check the source and date before using these numbers as current data.
- Write down the base and the method. In elasticity, growth-rate or percentage-point calculations, note which value you used as the base; a different method can change the result.
- Sort modules into folders. With your free account you can keep microeconomics, macroeconomics and econometrics packs in separate folders under My lessons.
See the PDF note-checking exercise to practise percent versus percentage points, and the example study pack for a mean and median calculation.
Frequently asked questions
Does it summarise graphs?
For videos that contain a presentation, slide images can be added to the pack, and the summary can explain a graph that was described in the lecture. Details of a graph that was only drawn on the board or shown without description may be missing from the transcript, so compare axes and shifts with the source.
Is it suitable for econometrics and mathematical economics?
Spoken lecture recordings and supported documents can be processed. Formulas, symbols and table values can be transferred incorrectly, so redo calculations yourself and compare the results with the source.
Can I make notes in another language from a textbook?
Yes. Source and output languages are chosen separately. Upload a chapter you are entitled to use as a document pack and choose one of 13 supported output languages; compare the translation of terms with the source.
Can I try it for free?
Yes. Without an account, you can process one short source in the workspace with a one-time guest trial on this device. To continue, create a free account; current allowances are listed on the Plans page.
Try it with your next lecture
Start with a microeconomics lecture.
Upload a short lecture recording as a guest and compare the assumptions and calculation steps in the summary with the source. When you want to continue, create your free account.