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Economic models you can actually see move. Every curve is computed and every shift is verified. Built for students who want intuition, not just diagrams.

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Educational purposes only, not financial advice. Graphl teaches which economic framework applies and how its mechanism works; it does not solve assessment problems for you.

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  3. Externalities & Pigouvian Taxes
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  5. Scenario

Micro Foundations · intermediate

Demand boom for a polluting good

What moves on the Externalities & Pigouvian Taxes diagram

  • D = MPBshifts right (small)

Demand shifts move both equilibria; the externalityexternalityA cost or benefit that lands on someone outside the transaction, pollution's harm, vaccination's protection. wedge, and the overproduction, persists at any demand level.

Watch it animateQuiz yourself on Externalities & Pigouvian Taxes

Step by step

  1. 1

    Start at equilibriumequilibriumThe point where opposing forces balance, quantity supplied equals quantity demanded, so there's no pressure for price to change. with the externalityexternalityA cost or benefit that lands on someone outside the transaction, pollution's harm, vaccination's protection. wedge visible.

  2. 2

    Demand for the polluting good booms.

  3. 3

    Both market and social optimum shift out, but the overproduction gap persists, now at a larger scale of harm.

Where this shows up

Examiners ask this as: polluting good demand, externality grows with output.

Other scenarios on Externalities & Pigouvian Taxes

A carbon tax is introduced →The pollution turns out worse →Cleaner technology shrinks the external cost →A dirtier process widens the external cost →Weak demand accidentally cuts the pollution →An industrial boom magnifies the market failure →