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Diminishing Marginal Benefit

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About This MicroSim

This MicroSim demonstrates the law of diminishing marginal benefit using a relatable pizza-eating scenario. As students click to eat each successive slice, they see that the first slice provides high satisfaction (+10) while each additional slice adds less and less benefit, eventually turning negative when they have eaten too much. A bar chart tracks the marginal benefit per slice, and a running total shows how overconsumption can actually reduce overall satisfaction.

How to Use

  1. Click "Eat Another Slice!" to consume your first pizza slice and observe the high marginal benefit displayed in the bar chart.
  2. Continue eating by clicking the button repeatedly. Watch as each new bar in the chart gets shorter, illustrating diminishing marginal benefit.
  3. Read the commentary below the stats panel for a plain-language explanation of what is happening at each stage.
  4. Notice when marginal benefit turns negative (around slice 7-8), shown as red bars below the zero line and declining total satisfaction.
  5. Click "Start Over" to reset the simulation and try to identify the optimal stopping point where marginal benefit approaches zero.

Iframe Embed Code

You can add this MicroSim to any web page by adding this to your HTML:

<iframe src="https://dmccreary.github.io/economics-course/sims/marginal-benefit-pizza/main.html"
        height="452px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan

Grade Level

9-12 (High School Economics)

Duration

10-15 minutes

Prerequisites

  • Basic understanding of the concept of benefit or satisfaction from consuming goods
  • Familiarity with reading bar charts

Activities

  1. Exploration (5 min): Eat all 8 slices one at a time and record the marginal benefit value for each slice. Identify the slice where total satisfaction peaks and begins to decline.
  2. Guided Practice (5 min): Reset the simulation. This time, stop eating when the marginal benefit of the next slice is close to zero. Discuss with a partner why a rational consumer would stop at this point and how this relates to the rule "consume until MB = MC."
  3. Assessment (5 min): Write a short paragraph explaining why the 1st slice gives more satisfaction than the 5th slice. Provide a real-life example of another good where you experience diminishing marginal benefit.

Assessment

  • Students can define marginal benefit as the additional satisfaction gained from consuming one more unit
  • Students can explain why marginal benefit decreases with each additional unit consumed
  • Students can identify the optimal quantity where a rational consumer should stop consuming

References

  1. Marginal Utility - Wikipedia - Overview of marginal utility theory and the law of diminishing marginal utility.
  2. Marginal Benefit - Investopedia - Explanation of marginal benefit with consumer decision-making examples.
  3. Utility Maximization - Khan Academy - Video lesson on how consumers maximize utility using marginal analysis.