PPolySim OS
For K-12 Students · Consumer Choice

Consumer Choice for a demand shock

Built for k-12 students learning it in middle or high school. Watch the idea come alive with plain-language steps and everyday examples — perfect for projects and homework. Simulate a demand shock live below — adjust the inputs and watch it respond, right in your browser.

Consumer ChoiceLive

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A consumer maximizes utility subject to a budget. Indifference curves connect equally-satisfying bundles; the budget line shows what income affords. The best choice is where the budget line just touches the highest reachable indifference curve — the tangency where the marginal rate of substitution equals the price ratio. Change a price and watch the optimal bundle move.

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Optimal X12.5
Optimal Y16.7
Utility14.4

Governing equation

Reading this result: With Cobb-Douglas preferences the optimal bundle spends a fixed income share on each good — here 50% of income (50) buys X and 50% buys Y, no matter how prices move; a price only changes how many units that fixed budget buys.

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Frequently asked questions

Is this good for k-12 students?
Yes — this version of "Consumer Choice for a demand shock" is framed for k-12 students learning it in middle or high school. Watch the idea come alive with plain-language steps and everyday examples — perfect for projects and homework.
Do I need to install anything?
No. It runs in any modern browser, free, with no account required.