Comparative advantage: why trade can help both sides

Grade 12 Social Studies Worksheet

Circle the best answer.

1. Read this first

   Use this

   Card A. Compare chart "Output per worker per day and a ledger for 100 workers each" (made up for practice), columns Line | Country N (wheat, cloth) | Country O (wheat, cloth) | Both (wheat, cloth): Output per worker per day | 9, 3 | 5, 5 | not applicable; Before: each splits workers 50–50 | 450, 150 | 250, 250 | 700, 400; After specializing: N all wheat, O all cloth | 900, 0 | 0, 500 | 900, 500; After trading: O sends 200 cloth for 400 wheat | 500, 200 | 400, 300 | 900, 500. Note: invented countries and figures, made up for practice. Each worker makes either wheat or cloth in a day. The trade price is 2 wheat for 1 cloth.

2. 1.

   Bo reads the last line of card A. After the trade, what does each country hold, compared with the line marked Before?

   • Both hold the same as before, since the trade is an even swap
   • N holds 900 wheat and O holds 500 cloth, the amounts they have after specializing
   • Each holds more wheat and more cloth: N has 500 and 200, O has 400 and 300
   • N holds more of both goods, but O holds less wheat than before
3. 2.

   A writer says trade helps Country N only at Country O's expense. Esme tests the claim with card A. What is the verdict?

   • Supported: N holds 900 wheat after specializing, more than O holds of anything
   • Supported: N gives up 200 cloth to O, so N's gain is O's loss
   • Not supported: the ledger covers 100 workers, so it cannot say anything about trade
   • Not supported: after trading both countries hold more of both goods than they did before

4. Use this

   Card A. Compare chart "Hours of work to make one unit" (made up for practice), columns Country | One bushel of wheat | One roll of cloth: Country P | 2 hours | 4 hours; Country Q | 6 hours | 6 hours. Note: invented countries and figures, made up for practice. Each country has the same number of hours to spend.

5. 3.

   Jun reads card A. Country P is faster at both goods. Which country should make cloth, and why?

   • Country Q, because Q takes 6 hours for each good and so loses less
   • Neither, because P is faster at both goods and so should make both
   • Country Q: a roll costs Q 1 bushel of wheat, but costs P 2 bushels
   • Country P, because it makes cloth in 4 hours, faster than Q's 6
6. 4.

   Country P can buy a roll of cloth from Q for 1.5 bushels of wheat. Kira uses card A. Does P gain from buying?

   • Yes: a roll costs P 2 bushels to make, and buying costs 1.5 bushels
   • No: P makes cloth in 4 hours, so buying at 6 hours' worth is slower
   • Yes, but if Q does not gain, since the price helps just one side
   • No: P pays 1.5 bushels and a roll costs P just 1 bushel to make
7. 5.

   Q asks 2.5 bushels of wheat for a roll of cloth. Luz uses card A. What should P do?

   • Not buy, because P should refuse any trade when it is faster at both of the goods
   • Buy, because Q needs 6 hours per roll, which makes cloth worth 2.5
   • Not buy: 2.5 bushels is more than the 2 bushels a roll costs P to make
   • Buy, because P is faster at both goods and can afford to pay the 2.5 bushels
8. 6.

   A writer says P, faster at both goods, gains nothing from trading with Q. Milo tests this with card A. What is the verdict?

   • Supported: Q cannot make anything more cheaply than P, so P has no reason to trade with Q in any case
   • Not supported: Q makes cloth in 6 hours, which is faster than P's wheat
   • Supported: P is faster because it has more workers, so it needs nothing from Q
   • Not supported: P gives up 2 bushels per roll, so any price under 2 from Q leaves P better off

9. Use this

   Card A. Compare chart "U.S. trade in goods and in services, billions of dollars" (U.S. Bureau of Economic Analysis and U.S. Census Bureau, international trade in goods and services, through FRED, retrieved Nov 14, 2026), columns Year | Goods exports | Goods imports | Goods balance | Services exports | Services imports | Services balance: 2019 | 1,655.1 | 2,512.4 | −857.3 | 898.4 | 576.5 | 321.9; 2024 | 2,079.7 | 3,292.5 | −1,212.8 | 1,156.7 | 829.4 | 327.3. Note: current dollars. A balance is exports minus imports. Each value is the sum of the twelve monthly values for the year.

10. 7.

    Noah writes one claim from card A about both years. Which claim does the card support best?

    • The U.S. has no comparative advantage in goods, since goods imports exceed exports
    • Goods ran a deficit and services a surplus in both years; the goods gap was far larger
    • Services exports were higher in 2024 than in 2019
    • The U.S. exported about 26 percent more goods in real terms in 2024
11. 8.

    A writer says a trade deficit shows a country has lost its comparative advantage. Pia tests the claim with card A. What is the verdict?

    • Supported: imports exceeded exports in goods in both years, so the advantage has been lost for good
    • Not supported: services ran a surplus while goods ran a deficit, so a total cannot rank advantages
    • Supported: the goods deficit widened, which means the country lost its advantage
    • Not supported: the card covers just 2019 and 2024, not the years between
12. 9.

    Ren compares growth from 2019 to 2024 on card A. Which statement about services is best supported?

    • Services imports grew by 252.9, which is a bigger dollar rise than exports
    • Services imports grew faster than exports, about 44 against 29 percent, yet services still ran a surplus
    • Services trade grew about 29 percent in real terms, since exports rose that much
    • Services exports grew faster than services imports, so the surplus widened a lot over the five years shown
13. 10.

    Tala wants to say in which good or service the U.S. has a comparative advantage. Which missing evidence would matter most?

    • What the U.S. gives up in other goods to make more of each, compared with other countries
    • The trade balance for 2020, to see whether the pattern held in a year between the two
    • The total number of items traded
    • The goods exports for 2025, to see whether the rise continued beyond the card's last year