Shifts in Supply
Unit 2 · Lesson 2.6 · Last updated June 2026
A 45-minute lesson where students learn the four shifters of supply, practice shifting the supply curve, and work through mixed supply and demand scenarios to find new market equilibria.
Overview
In this lesson, students are introduced to the major shifters of supply. Students practice shifting the supply curve on the market model and explain how shortages and surpluses result in a new equilibrium.
Learning Objectives
- Identify shifters of the product supply curve and determine the appropriate shift given a scenario.
- Use the concepts of shortage and surplus to explain the change in the market equilibrium price and equilibrium quantity that results from a shift of the product supply curve.
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Materials
- Instruction Slides (display during class period)
- Student Handout pp. 4–7 (1 copy per student)
- KEY Source Practice p. 8 (class set — 1 copy per pair of students)
Lesson Sequence
Slides 2–4
- Display Slide 2 and distribute 1 copy of Student Handout to each student. Click to reveal the remaining text and alert students that this activator will help them practice for both Unit 2 assessments. Give students 6 minutes to complete the activator working alone or with a peer. (Additional educator tips and suggested answers are in the notes section throughout Instruction Slides.)
- Display Slide 3. Distribute 1 copy of KEY Source Practice to each pair and allow pairs 3 minutes to review and make note of elements that remain unclear.
- Review KEY Source Practice as a class, allowing students to share "matches" that are still unclear. Once misconceptions have been clarified, ask students if there were any matches they made that KEY Source Practice did not. Note: Some students will see connections not listed in the key — if their response is grounded in sound economic reasoning, celebrate their ability to make additional connections.
- Display Slide 4. Introduce the learning objectives.
Slides 5–33
- Proceed through Slides 5–8 to review movements along the supply curve, introduce shifts in supply, and show how supply shifts are illustrated in the product market model. Alert students to the stumbling blocks (as indicated by the yellow warning graphic on Slides 6 and 7). Remind students to continue using "right" for an increase and "left" for a decrease, as they did when practicing shifts in demand.
- Display Slide 9. Tell students to "wear their Firm Hats" when thinking about supply shifts and consider how their firms would respond to each shifter (Lesson 2.3). Introduce the three shifters of supply. Note: Many textbooks and online resources list additional shifters (taxes, availability of resources, etc.), but many of those ultimately boil down to costs of production.
- Proceed to Slide 10. Pause for 30 seconds and direct students to use the right-hand side of Student Handout to sketch 1 or 2 graphs demonstrating a shift in supply.
- Using Slides 11–14, guide students through each shifter, pausing between each to allow 1 minute for students to generate their own examples. Students can draw pictures, sketch graphs, and/or write responses on Student Handout. Ask for 1 or 2 examples to share with the class. Alert students to the stumbling block on Slide 13: similar to shifts in demand, the most confusing supply shift is expectations. Pro Tip: Student Handout is formatted so it can easily become a review tool when students fold it between their examples/sketches and the key ideas.
- Display Slide 15. Pause to allow students to ask questions before moving into the practice portion.
- Proceed to Slide 16. Direct students to discuss with a peer which factor they feel most confident about and least confident about. Students put a "!" next to the shifter they are least confident about on Student Handout.
- Progress through Slides 17–18. Allow students 30 seconds to solve Practice 1 on Slide 18 using scrap paper, individually or with a peer.
- After 30 seconds, proceed to Slide 19 to discuss the solution. Remind students that the new equilibrium is not achieved instantaneously but is the result of consumers and suppliers changing their behavior in response to market signals.
- Display Slide 20 to prompt students to determine if there was a shortage or surplus at the original equilibrium price. Reveal the solution on Slide 21 and explain the key points on the graph.
- Display Slide 22 and allow students 30 seconds to solve Practice 2 using scrap paper, individually or with a peer.
- Progress through Slides 23–25 to discuss the solution to Practice 2 and determine whether there was a shortage or a surplus at the original equilibrium price.
- Proceed to Slide 26. Direct students to the "Practice Shifts" section of Student Handout. Read the instructions to students and alert them that they will encounter both demand and supply shifts, so they need to determine which curve shifts. Encourage students to reference 2.5 Student Handout (Shifts in Demand) as needed. Allow 12 minutes to complete the practice problems individually or with a peer.
- Review the solutions using Slides 27–33.
Slides 34–36
- Advance to Slide 34. Direct students to put their notes on supply and demand shifts away.
- Proceed through Slides 35–36 to frame the summarizer. Instruct students to discuss their responses with a peer.
Aligned Standards
Voluntary National Content Standards in Economics
What Educators Are Saying
Another great idea from Econiful to review content vocabulary! Full disclosure, I used this idea but added my own content in the Supply & Demand unit. I started this with my EL students by only having 6 cards. Then 12. Then 18. Then 24. It helped for them to add layers of difficulty this way. One suggestion that THEY made was to have an odd number of cards because two groups tied and they are VERY competitive!
I liked the graphic practice integrated into the lesson and slides.
I like how simple it is. Students GOT it. They were confident in their graphs. I added scenarios to each slide and used many of your examples in the notes section. After I gave the scenario, students graphed it, then double-checked with their neighbor, then I graphed it on the board. They checked each other's work.