Week 13 — Assignment (Adaptive Learning) · Comparative Advantage & the Trade Balance Problem Set

Course: Principles of Macroeconomics (ECON 2) · Silver Oak University (fictional sample) · Prof. Ashford
Objective 8 · SLO A & B · Assignment 13 of 14 · 100 points
This is the configured (adaptive) variant. An AI coach gives you the problems one at a time, grades each against an embedded rubric, lets you retry a fresh version, and produces a self-scored report. You submit the report (first line STUDENT'S SCORE: X/100) + your chat share link. (The traditional, instructor-graded version is in I-assignment-and-rubric-week-13-traditional.md.)

How to run this

1. Open an approved chatbot (Gemini, Claude, ChatGPT). Copy the whole gray box and paste it as one message.
2. Solve each problem; the coach grades it, teaches the gaps, and offers a fresh variant to raise your score.
3. When you get the report, submit it (it starts with STUDENT'S SCORE: X/100) plus your chat share link in Canvas. Due Sun, Nov 29.

You are my assignment coach and grader for Week 13 of Principles of Macroeconomics (ECON 2)
at Silver Oak University. Give me the problems below ONE AT A TIME, let me solve each, grade
my answer against the rubric, show me how to improve, and let me re-try a fresh version to
raise my score. Grade ONLY against the answer key and rubric below — never invent problems,
answers, or scores. Redo any arithmetic yourself and SHOW YOUR WORK before telling me I'm
wrong. Score honestly; a wrong answer scores low, a strong answer earns full marks.

HARD RULES (never break these): (1) never invent or misattribute a quotation, study,
statistic, or real-world data figure; (2) never take a partisan side on any contested
question — present reasoning fairly and never declare free trade OR tariffs objectively
"correct."

START: greet me in 1–2 sentences, ask my FIRST NAME, then give Problem 1 exactly as written.
If I answer without giving my name, keep going but ask before the final report. ONE problem
at a time; never show the whole set, the answers, the variants, or the rubric. After each
answer: grade it, say what I did well, TEACH the gap, then offer a re-attempt on the FRESH
VARIANT (update my score to my BEST attempt, capped at full marks). Judge meaning, not
wording. Every message ends with a problem, a question, or a next step.

================= PROBLEM 1 (25 pts) — Computing opportunity cost & assigning comparative advantage =================
PROBLEM: "Eastvale produces 8 wheat OR 4 cloth per worker-day. Westhaven produces 9 wheat OR
3 cloth per worker-day. (a) Compute each country's opportunity cost of 1 unit of cloth, in
wheat. (b) Compute each country's opportunity cost of 1 unit of wheat, in cloth. (c) Which
country has the comparative advantage in cloth, and which in wheat? (d) Does either country
have the absolute advantage in anything? Does that change your answer to (c)?"
VETTED ANSWER: (a) Eastvale: 8÷4 = 2 wheat per cloth. Westhaven: 9÷3 = 3 wheat per cloth.
(b) Eastvale: 4÷8 = 0.5 (½) cloth per wheat. Westhaven: 3÷9 ≈ 0.333 (⅓) cloth per wheat.
(c) Eastvale has the comparative advantage in cloth (2 wheat < Westhaven's 3 wheat).
Westhaven has the comparative advantage in wheat (⅓ cloth < Eastvale's ½ cloth). (d)
Westhaven has the absolute advantage in wheat (9 > 8 per worker-day); the two tie in cloth
(4 vs. 3 — actually Eastvale produces MORE cloth per worker-day here, so Eastvale also holds
the absolute advantage in cloth). This does NOT change (c) — Eastvale still has the
comparative advantage in cloth because its OPPORTUNITY COST is lower, regardless of who
produces more.
RUBRIC: 25 = all four parts correct with the arithmetic shown. 15–20 = (a)–(c) correct, (d)
vague or doesn't clearly separate absolute from comparative. 8–14 = one opportunity-cost
ratio flipped (e.g., stating Eastvale's cloth cost as ½ instead of 2) or one comparative-
advantage assignment wrong. 0–7 = mostly wrong or assumes the "more productive" country gets
both.
FRESH VARIANT: "Milltown produces 10 wheat OR 5 cloth per worker-day. Bayside produces 12
wheat OR 4 cloth per worker-day. (a) Opportunity cost of 1 cloth for each, in wheat? (b)
Opportunity cost of 1 wheat for each, in cloth? (c) Who has the comparative advantage in
which good?" ANSWER: (a) Milltown 10÷5=2 wheat; Bayside 12÷4=3 wheat. (b) Milltown 5÷10=0.5
cloth; Bayside 4÷12≈0.333 cloth. (c) Milltown has the comparative advantage in cloth (2<3);
Bayside has the comparative advantage in wheat (0.333<0.5).

================= PROBLEM 2 (25 pts) — Terms of trade & proving both countries gain =================
PROBLEM: "Using Eastvale (8 wheat or 4 cloth per worker-day) and Westhaven (9 wheat or 3
cloth per worker-day), each with 10 worker-days: (a) What is the mutually beneficial range
of terms of trade (wheat per cloth)? (b) BEFORE trade, Eastvale makes 56 wheat and 12 cloth
(7 worker-days on wheat, 3 on cloth); Westhaven makes 27 wheat and 21 cloth (3 worker-days
on wheat, 7 on cloth). After FULL specialization (Eastvale all-cloth, Westhaven all-wheat),
how much does each country produce? (c) At a terms of trade of 2.5 wheat per cloth, if
Eastvale trades 24 units of cloth to Westhaven, how much wheat does Eastvale receive? (d)
Show that BOTH countries end up with MORE of BOTH goods after trade than before trade."
VETTED ANSWER: (a) Between Eastvale's own cost (2 wheat per cloth) and Westhaven's own cost
(3 wheat per cloth) — i.e., between 2 and 3 wheat per cloth. (b) Eastvale specializes fully
in cloth: 10 worker-days × 4 = 40 cloth, 0 wheat. Westhaven specializes fully in wheat: 10 ×
9 = 90 wheat, 0 cloth. (c) 24 cloth × 2.5 wheat/cloth = 60 wheat. (d) Eastvale after trade:
40 − 24 = 16 cloth kept + 60 wheat received. Compare to BEFORE (56 wheat, 12 cloth): 60 > 56
wheat (gain) AND 16 > 12 cloth (gain). Westhaven after trade: 90 − 60 = 30 wheat kept + 24
cloth received. Compare to BEFORE (27 wheat, 21 cloth): 30 > 27 wheat (gain) AND 24 > 21
cloth (gain). BOTH countries gained on BOTH goods.
RUBRIC: 25 = all four parts correct with full arithmetic. 15–20 = (a)–(c) correct, (d)
incomplete (checks only one country or one good). 8–14 = range or specialization output
wrong, OR the trade-quantity arithmetic (24×2.5=60) is right but not compared back to the
before-trade numbers. 0–7 = mostly wrong or claims one country loses without checking the
arithmetic.
FRESH VARIANT: "Same countries, but Eastvale trades 30 units of cloth instead of 24 (still
at 2.5 wheat per cloth). (a) How much wheat does Eastvale receive? (b) What are the exact
post-trade totals for each country? (c) Does EVERY comparison still show a gain for both
countries on both goods — check each one." ANSWER: (a) 30 × 2.5 = 75 wheat. (b) Eastvale: 40
− 30 = 10 cloth + 75 wheat. Westhaven: 90 − 75 = 15 wheat + 30 cloth. (c) Eastvale: wheat
75>56 (gain), cloth 10<12 (a LOSS on cloth this time — the larger trade quantity means
Eastvale kept too little cloth for itself). Westhaven: wheat 15<27 (a loss), cloth 30>21
(gain). This variant is DESIGNED to show that not every trade quantity within the mutually
beneficial ToT range preserves gains on BOTH goods for BOTH countries — the quantity traded
matters, not just the ratio; full credit requires noticing and stating this explicitly.
================= PROBLEM 3 (25 pts) — The trade balance (NX) =================
PROBLEM: "A fictional economy's exports (X) total $300 million and its imports (M) total
$350 million this quarter. (a) Compute net exports (NX). (b) Is this a trade surplus or a
trade deficit? (c) Explain, in 2–3 sentences, why this NX figure by itself does NOT tell you
whether the economy is 'doing well' or 'doing poorly.'"
VETTED ANSWER: (a) NX = X − M = 300 − 350 = −$50 million. (b) A trade DEFICIT (negative NX
means imports exceeded exports). (c) NX is a fact about the flow of goods and money, not a
verdict on economic health — a deficit can coincide with strong domestic consumer demand
pulling in more imports, or with foreign investment flowing INTO the country to help fund
it; evaluating whether it's a "problem" requires more context (why is it happening? what's
funding it?) than the single NX number provides.
RUBRIC: 25 = (a) and (b) correct AND (c) correctly explains that NX needs context, without
declaring the deficit automatically good or bad. 15–20 = (a)–(b) correct, (c) vague or just
restates the definition without explaining WHY context matters. 8–14 = (a) correct but (b)
mislabeled (calls it a surplus) or (c) treats the deficit as an automatic verdict either way.
0–7 = (a) wrong (arithmetic error).
FRESH VARIANT: "Same setup, but X = $450 million and M = $400 million this quarter. (a)
Compute NX. (b) Surplus or deficit? (c) Does a SURPLUS automatically mean the economy is
doing well? Briefly explain." ANSWER: (a) 450 − 400 = $50 million. (b) A trade SURPLUS. (c)
No — a surplus, too, is a fact about flows; it can coincide with weak domestic demand (fewer
imports because consumers are spending less) rather than necessarily reflecting strength,
so it also needs context before being judged good or bad.

================= PROBLEM 4 (25 pts) — Free trade vs. tariffs, evenhandedly =================
PROBLEM: "A country is debating whether to place a tariff on imported cloth to protect its
domestic cloth industry. In 4–5 sentences: (a) state the strongest case FOR free trade
(against the tariff) here, (b) state the strongest case FOR the tariff (for protection), and
(c) identify which parts of your answer are POSITIVE claims and which are NORMATIVE
judgments. Do not declare which policy is objectively correct."
VETTED ANSWER: (a) Free-trade case: specialization by comparative advantage raises the
country's TOTAL available output (a positive result); consumers get access to more cloth at
lower prices; a tariff would raise the domestic price of cloth and shrink the total gains
from trade. (b) Tariff case: the domestic cloth industry's specific workers and communities
can be genuinely hurt by import competition, even while the country gains on net — a real
distributional cost; protecting the industry may be judged worth the total-output cost for
reasons of employment, regional stability, or (in some arguments) national-security/infant-
industry considerations. (c) POSITIVE: "specialization raises total output," "a tariff
raises the domestic price of cloth," "specific workers/communities can lose jobs to import
competition" — all testable, well-established mechanisms. NORMATIVE: "the total-output gain
is worth the job losses" or "protecting these workers is worth the total-output cost" — both
are value judgments about how to weigh concentrated costs against diffuse benefits, and
reasonable people disagree.
RUBRIC: 25 = both cases presented at genuine strength (not a strawman on either side) AND
the positive/normative split is explicit and correct. 15–20 = both cases present but one is
weaker/thinner, or the positive/normative split is attempted but blurs a claim. 8–14 = only
one case argued strongly, OR no positive/normative distinction attempted. 0–7 = declares one
policy objectively correct, or presents only one side.
FRESH VARIANT: "Same setup, but for a tariff on imported STEEL instead of cloth. Argue the
same three parts (a)/(b)/(c)." ANSWER: structurally identical — (a) free trade raises total
output, cheaper steel for downstream manufacturers and consumers, a steel tariff would raise
domestic steel prices; (b) domestic steel workers/communities/plants can be hurt by import
competition even as the country gains on net, and some policymakers argue steel merits
protection on national-security grounds (a steel industry is sometimes framed as
defense-critical); (c) same positive/normative split, applied to steel instead of cloth.

================= COMPLETION =================
After all four problems (and any re-attempts), produce EXACTLY:
    STUDENT'S SCORE: X/100
    WEEK 13 ASSIGNMENT — Comparative Advantage & the Trade Balance
    Student: [name] | Date: ___
    Problem 1: a/25 — [one-line note]
    Problem 2: b/25 — [one-line note]
    Problem 3: c/25 — [one-line note]
    Problem 4: d/25 — [one-line note]
    Strongest skill: ___
    Worth another look: ___
Then say, verbatim: "Copy this entire report AND your share link to this chat, and submit both
in Canvas for this assignment." End with one genuine sentence of encouragement.

Instructor grading note + rubric (for Canvas)

Record the AI score (line 1); spot-check a sample against the chat share link. The embedded key makes scores consistent across chatbots. Summary rubric (each problem to 25, total 100):

Quantitative gate: PASS — every number pre-computed/re-verified: P1 8÷4=2 and 4÷8=0.5 (Eastvale), 9÷3=3 and 3÷9≈0.333 (Westhaven) — variant 10÷5=2, 5÷10=0.5 (Milltown), 12÷4=3, 4÷12≈0.333 (Bayside); P2 specialization 10×4=40 cloth / 10×9=90 wheat, trade 24×2.5=60 wheat, post-trade Eastvale 60 wheat/16 cloth (both > pre-trade 56/12), Westhaven 30 wheat/24 cloth (both > pre-trade 27/21) — variant at C=30 deliberately shows a trade quantity that does NOT preserve gains on both goods, testing that students notice quantity matters, not just the ToT ratio; P3 300−350=−50 and variant 450−400=50.
Graph-logic check: PASS — every comparative-advantage/trade claim verified: comparative advantage (opportunity cost) correctly distinguished from absolute advantage (raw output) in P1(d); the mutually-beneficial-range logic (strictly between 2 and 3 wheat per cloth) correct in P2(a); NX sign and surplus/deficit labeling correct in P3; the trade-deficit/surplus-≠-verdict framing applied neutrally in P3(c) and its variant; free trade and tariffs both argued at full strength with the positive/normative split explicit in P4, no verdict declared.

Canvas placement block

canvas_object    = Assignment
title            = "Week 13 Assignment — Comparative Advantage & the Trade Balance (adaptive)"
assignment_group = "Assignments"
points_possible  = 100
grading_type     = points
submission_types = [online_text_entry, online_url]
due_offset_days  = 6
published        = true
submission_note  = "Paste the AI summary report (score on line 1) + the chat share link."
provenance       = "~ Prof. Ashford's edition · Fall 2026 · built with thecoursemaker.com"

Traditional variant — for comparison. This course is configured adaptive learning, so the actual Week-13 assignment is the AI-coached version in I-assignment-and-rubric-week-13.md. This file shows the same problem set built the traditional way — students complete it and submit; the instructor grades against the rubric. (Choosing assignment_type = traditional at setup generates this style.)

Course: Principles of Macroeconomics (ECON 2) · Silver Oak University (fictional sample) · Prof. Ashford
Objective 8 · SLO A & B · Assignment 13 of 14 · 100 points · Due Sun, Nov 29

The Assignment

Show your work and write your interpretations in complete sentences. Submit as a document or text entry.

Problem 1 — Computing opportunity cost & assigning comparative advantage (25 pts). Eastvale produces 8 wheat OR 4 cloth per worker-day. Westhaven produces 9 wheat OR 3 cloth per worker-day.
(a) Compute each country's opportunity cost of 1 unit of cloth, in wheat.
(b) Compute each country's opportunity cost of 1 unit of wheat, in cloth.
(c) Which country has the comparative advantage in cloth, and which in wheat?
(d) Does either country have the absolute advantage in anything? Does that change your answer to (c)?

Problem 2 — Terms of trade & proving both countries gain (25 pts). Each country has 10 worker-days. Before trade, Eastvale makes 56 wheat and 12 cloth (7 worker-days on wheat, 3 on cloth); Westhaven makes 27 wheat and 21 cloth (3 worker-days on wheat, 7 on cloth).
(a) What is the mutually beneficial range of terms of trade (wheat per cloth) between these two countries?
(b) After full specialization (Eastvale all-cloth, Westhaven all-wheat), how much does each country produce?
(c) At a terms of trade of 2.5 wheat per cloth, if Eastvale trades 24 units of cloth to Westhaven, how much wheat does Eastvale receive?
(d) Show that BOTH countries end up with MORE of BOTH goods after trade than before trade.

Problem 3 — The trade balance (25 pts). A fictional economy's exports (X) total $300 million and its imports (M) total $350 million this quarter.
(a) Compute net exports (NX).
(b) Is this a trade surplus or a trade deficit?
(c) In 2–3 sentences, explain why this NX figure by itself does NOT tell you whether the economy is "doing well" or "doing poorly."

Problem 4 — Free trade vs. tariffs, evenhandedly (25 pts). A country is debating whether to place a tariff on imported cloth to protect its domestic cloth industry. In 4–5 sentences:
(a) state the strongest case FOR free trade (against the tariff),
(b) state the strongest case FOR the tariff (for protection),
(c) identify which parts of your answer are POSITIVE claims and which are NORMATIVE judgments. Do not declare which policy is objectively correct.

AI note. This is the traditional format — submit your own work. You may use an approved chatbot to check a definition, but add a one-line note of which tool and how. (In the adaptive version, working the problems with the chatbot is the activity.)

Grading rubric — 100 points

Instructor answer key & worked solutions — REMOVE BEFORE PUBLISHING TO STUDENTS

• P1: (a) Eastvale: 8÷4 = 2 wheat per cloth. Westhaven: 9÷3 = 3 wheat per cloth. (b) Eastvale: 4÷8 = 0.5 (½) cloth per wheat. Westhaven: 3÷9 ≈ 0.333 (⅓) cloth per wheat. (c) Eastvale has the comparative advantage in cloth (2 wheat < Westhaven's 3 wheat). Westhaven has the comparative advantage in wheat (⅓ cloth < Eastvale's ½ cloth). (d) Westhaven has the absolute advantage in wheat (9 > 8); Eastvale actually produces more cloth per worker-day (4 > 3), so Eastvale holds the absolute advantage in cloth too. This does NOT change (c) — Eastvale keeps the comparative advantage in cloth because its opportunity cost is lower, regardless of who produces more. (Verified.)
• P2: (a) Between Eastvale's own cost (2 wheat per cloth) and Westhaven's own cost (3 wheat per cloth) — the range is 2 to 3 wheat per cloth. (b) Eastvale specializes fully in cloth: 10 × 4 = 40 cloth, 0 wheat. Westhaven specializes fully in wheat: 10 × 9 = 90 wheat, 0 cloth. (c) 24 cloth × 2.5 wheat/cloth = 60 wheat. (d) Eastvale after trade: 40 − 24 = 16 cloth kept + 60 wheat received. Compare to before (56 wheat, 12 cloth): 60 > 56 wheat AND 16 > 12 cloth — gains on both. Westhaven after trade: 90 − 60 = 30 wheat kept + 24 cloth received. Compare to before (27 wheat, 21 cloth): 30 > 27 wheat AND 24 > 21 cloth — gains on both. (Verified — both countries gained on both goods.)
• P3: (a) NX = 300 − 350 = −$50 million. (b) A trade DEFICIT (negative NX = imports exceeded exports). (c) NX is a fact about the flow of goods and money, not a verdict on economic health — a deficit can coincide with strong domestic consumer demand pulling in more imports, or with foreign investment flowing IN to help fund it; judging whether it's a "problem" needs more context (why is it happening? what's funding it?) than the single NX number provides. (Verified.)
• P4: (a) Free-trade case: specialization by comparative advantage raises the country's TOTAL available output (a positive result, verified in P2); consumers get more cloth at lower prices; a tariff would raise the domestic price of cloth and shrink the total gains from trade. (b) Tariff case: the domestic cloth industry's specific workers and communities can be genuinely hurt by import competition, even while the country gains on net — a real distributional cost; protecting the industry may be judged worth the total-output cost for reasons of employment, regional stability, or (in some arguments) national-security/infant-industry considerations. (c) POSITIVE: "specialization raises total output," "a tariff raises the domestic price of cloth," "specific workers/communities can lose jobs to import competition" — all testable, well-established mechanisms. NORMATIVE: "the total-output gain is worth the job losses" or "protecting these workers is worth the total-output cost" — value judgments about weighing concentrated costs against diffuse benefits; economists and policymakers genuinely disagree, and no verdict should be graded as objectively "correct."

Quantitative gate: PASS — all numbers re-computed in Python (P1: 8÷4=2, 4÷8=0.5, 9÷3=3, 3÷9≈0.333; P2: 10×4=40, 10×9=90, 24×2.5=60, post-trade 60/16 vs. pre-trade 56/12 for Eastvale and 30/24 vs. 27/21 for Westhaven, all gains confirmed; P3: 300−350=−50).
Graph-logic check: PASS — every comparative-advantage/trade claim verified: comparative advantage (opportunity cost) correctly distinguished from absolute advantage (raw output); the mutually-beneficial-range logic (strictly between 2 and 3 wheat per cloth) correct; NX sign and deficit labeling correct; the trade-deficit-≠-verdict framing applied neutrally; free trade and tariffs both argued at full strength with the positive/normative split explicit, no verdict declared.

Quality gate (self-checked): distractors/traps named: absolute-vs-comparative confusion, flipped opportunity-cost ratio, terms of trade outside the mutually beneficial range, treating a trade deficit (or surplus) as an automatic verdict, declaring one trade policy objectively correct.

Canvas placement block

canvas_object    = Assignment
title            = "Week 13 Assignment — Comparative Advantage & the Trade Balance (traditional)"
assignment_group = "Assignments"
points_possible  = 100
grading_type     = points
submission_types = [online_upload, online_text_entry]
due_offset_days  = 6
rubric_ref       = "w13-assignment-rubric"
published        = true
provenance       = "~ Prof. Ashford's edition · Fall 2026 · built with thecoursemaker.com"