Comparative Advantage and the Gains from Trade · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Why even the best can gain by trading

Civics & Economics · Economics · ages 15-16
Name ______________________   Date ____________
  1. In Alvia, one worker in one day makes 10 wheat or 5 cloth, with a constant trade-off. How much wheat does making 1 cloth cost?

    Answer: ______________

  2. With resources held equal, what distinguishes absolute advantage from comparative advantage?

    • Output versus opportunity cost
    • Opportunity cost versus total output
    • Output per worker versus output per hour
  3. In Betta, one worker in one day makes 4 wheat or 4 cloth, with a constant trade-off. What is the wheat cost of 1 cloth?

    • 4 wheat
    • 2 wheat
    • 1 wheat
  4. With constant opportunity costs and no trade costs, what can both countries gain from specialising by comparative advantage and trading on mutually beneficial terms?

    • More of both goods produced by each country
    • Consumption beyond domestic production limits
    • A larger productive capacity without extra resources
  5. In one worker-day, Alvia can make 10 wheat or 5 cloth; Betta can make 4 wheat or 4 cloth. Trade-offs are constant. Which country has the comparative advantage in cloth?

    • Alvia, since it makes more wheat
    • Betta, with the lower sacrifice
    • Neither, since Alvia is better at both
  6. One country has absolute advantage in both goods, but the two countries have different constant opportunity costs. Why can they still gain from trade?

    • Each can specialise at a lower relative sacrifice
    • The less productive country has the lower cost in both goods
    • Equal output per worker is required before either country gains
  7. Alvia imports cloth from Betta through mutually beneficial trade in the two-good model. A tariff blocks these imports to protect Alvia's cloth makers. What is the wider cost?

    • Lost gains from specialisation
    • Only a transfer to producers, with no lost trade gains
    • Higher consumption of both goods through self-sufficiency
  8. In a two-good model with different constant opportunity costs and no trade costs, any swap rate allows both countries to gain from specialisation and trade.

    Circle one:   True   False

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Answer key

For grown-ups. Fold this page away before handing over the rest.

Why even the best can gain by trading W1-mt_gcGxu7E2Y8-s1

  1. 2 · Divide 10 by 5: each cloth sacrifices 2 wheat.
  2. Output versus opportunity cost · Absolute advantage compares output using equal resources. Comparative advantage compares the alternative output sacrificed per unit, which is opportunity cost.
  3. 1 wheat · Divide 4 by 4: each cloth sacrifices 1 wheat.
  4. Consumption beyond domestic production limits · Trade can allow each country to consume a combination it could not produce alone. Trade itself does not increase productive capacity or make each country produce more of both goods.
  5. Betta, with the lower sacrifice · Alvia gives up 2 wheat per cloth; Betta gives up 1. Betta has the lower opportunity cost.
  6. Each can specialise at a lower relative sacrifice · Different opportunity costs give each country a comparative advantage in one good. Each can specialise where its sacrifice is lower relative to its partner and trade on beneficial terms.
  7. Lost gains from specialisation · Blocking the beneficial exchange removes consumption gains from specialisation and trade. Protection may help cloth makers, but that does not eliminate the lost gains.
  8. False · Both gain only at a rate strictly between their two opportunity costs; an endpoint leaves one side indifferent.
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