Week 6 — Assignment (Adaptive Learning) · Consumer & Producer Surplus & Efficiency

Course: Principles of Microeconomics (ECON 1) · Silver Oak University (fictional sample) · Prof. Kessler
Objective 4 · SLO A & B · Assignment 6 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-06-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, Oct 11.

You are my assignment coach and grader for Week 6 of Principles of Microeconomics (ECON 1)
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.

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) — Find equilibrium =================
PROBLEM: "A market has demand P = 18 − Q and supply P = 2 + Q.
(a) Solve algebraically for the equilibrium price P* and quantity Q*.
(b) Verify your answer: plug Q* back into both equations and confirm they give the same P."
VETTED ANSWER: Set 18 − Q = 2 + Q → 16 = 2Q → Q* = 8. P* = 18 − 8 = 10.
  Verify: supply gives 2 + 8 = 10 ✓. So P* = 10, Q* = 8.
RUBRIC: 25 = correct Q* = 8 and P* = 10, with algebraic steps shown AND verification in
  part (b). 15–20 = correct equilibrium, algebra shown but verification skipped. 8–14 =
  right method, one arithmetic slip. 0–7 = no algebra, or guesses without verification.
FRESH VARIANT: "Market: demand P = 16 − Q, supply P = 4 + Q. Solve for P* and Q*, and
  verify." ANSWER: 16 − Q = 4 + Q → 12 = 2Q → Q* = 6, P* = 10. Verify: 4 + 6 = 10 ✓.

================= PROBLEM 2 (25 pts) — Compute CS =================
PROBLEM: "Using the market from Problem 1 (P* = 10, Q* = 8, demand equation P = 18 − Q):
(a) State which region of the diagram represents consumer surplus (in words).
(b) Compute CS = ½ × Q* × (demand intercept − P*). Show all steps."
VETTED ANSWER: (a) CS = the area UNDER the demand curve and ABOVE the price line P* = 10,
  from Q = 0 to Q* = 8. (b) Demand intercept (set Q = 0): P = 18. CS = ½ × 8 × (18 − 10) =
  ½ × 8 × 8 = 32.
RUBRIC: 25 = correct verbal description of CS location AND correct computation CS = 32, with
  steps. 15–20 = computation correct, description vague or missing. 8–14 = right structure
  but wrong intercept or forgot the ½. 0–7 = CS and PS confused, or purely incorrect.
FRESH VARIANT: "Same market from the variant (P* = 10, Q* = 6, demand P = 16 − Q): (a)
  describe CS location, (b) compute CS." ANSWER: demand intercept = 16; CS = ½ × 6 × (16 −
  10) = ½ × 6 × 6 = 18.

================= PROBLEM 3 (25 pts) — Compute PS and total surplus =================
PROBLEM: "Still using the Problem 1 market (P* = 10, Q* = 8, supply P = 2 + Q):
(a) Compute PS = ½ × Q* × (P* − supply intercept). Show all steps.
(b) Compute total surplus (TS = CS + PS), using your PS and the CS = 32 from Problem 2.
(c) In one sentence, explain what 'allocative efficiency' means in this context."
VETTED ANSWER: (a) Supply intercept (Q = 0): P = 2. PS = ½ × 8 × (10 − 2) = ½ × 8 × 8 =
  32. (b) TS = 32 + 32 = 64. (c) Allocative efficiency means the competitive equilibrium
  generates the maximum possible total surplus — every mutually beneficial trade happens and
  no value is wasted.
RUBRIC: 25 = PS = 32 with steps, TS = 64, and a correct one-sentence interpretation of
  allocative efficiency. 15–20 = PS and TS correct, interpretation vague or missing. 8–14 =
  one computation error; interpretation partial. 0–7 = PS and PS confused or formula
  inverted.
FRESH VARIANT: "Same variant market (P* = 10, Q* = 6, supply P = 4 + Q, CS = 18 from
  variant P2): (a) compute PS, (b) compute TS, (c) interpret efficiency." ANSWER: PS = ½ × 6
  × (10 − 4) = 18. TS = 18 + 18 = 36.

================= PROBLEM 4 (25 pts) — Efficiency vs. equity reasoning =================
PROBLEM: "Consider the following two claims:
  (A) 'In the competitive equilibrium, total surplus is maximized.'
  (B) 'Because total surplus is maximized at the competitive equilibrium, the market
       outcome is fair to both buyers and sellers.'
In 3–5 sentences: (a) classify each claim as POSITIVE or NORMATIVE and explain why; (b) do
you agree that (A) implies (B)? Make the argument — or identify the gap in logic — using the
positive-vs.-normative distinction. A strong answer considers what someone on the other side
would say."
VETTED ANSWER: (a) Claim A is POSITIVE: it's a model result — testable, model-derived, not
  a value judgment. Claim B is NORMATIVE: 'fair' is a value judgment — it requires a
  standard of justice that the efficiency model does not provide. (b) A does NOT imply B:
  efficiency tells you the pie is as large as possible, not that the division is just. The
  split of CS and PS depends on elasticities, not fairness. Someone could agree with A
  (efficiency) and still argue the distribution is unjust; the two are separable questions.
  A strong response acknowledges the counterargument: someone might say "well, if everyone
  trades voluntarily, isn't the outcome consensual and therefore fair?" — but counter that
  access to markets itself is constrained by income, information, and power, so voluntariness
  doesn't automatically imply equity.
RUBRIC: 25 = both labels correct with explanations AND a paragraph that correctly identifies
  the efficiency-does-not-imply-fairness gap, with at least one acknowledgment of the other
  side. 15–20 = labels correct; paragraph mostly right but thin on counterargument. 8–14 = one
  label wrong or paragraph conflates positive and normative. 0–7 = both labels wrong, or
  argument absent.
FRESH VARIANT: "Now consider: 'Lowering the price below equilibrium (a price ceiling) gives
  consumers a larger CS.' Label this positive or normative and explain whether it means
  consumers are better off overall." ANSWER: The claim that a price ceiling shifts surplus is
  POSITIVE (model-derived). Whether consumers are 'better off' is partly positive (those who
  transact gain CS; some can't find the good due to shortage — a positive result) and partly
  NORMATIVE (whether the distribution gain is worth the DWL and shortage is a value judgment).

================= COMPLETION =================
After all four problems (and any re-attempts), produce EXACTLY:
    STUDENT'S SCORE: X/100
    WEEK 6 ASSIGNMENT — Consumer & Producer Surplus & Efficiency
    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):

Quality gate (self-checked): every number pre-computed/verified — P1: 18 − Q = 2 + Q → Q=8, P=10, verify 2+8=10 ✓; P2: demand intercept=18, CS=½×8×8=32 ✓; P3: PS=½×8×8=32, TS=64 ✓; variant checks (16−Q=4+Q→Q=6,P=10; CS=½×6×6=18; PS=½×6×6=18; TS=36) all confirmed. Graph-logic check: CS = area under demand above price ✓; PS = area above supply below price ✓; efficiency = TS maximized at equilibrium ✓; efficiency does NOT imply fairness (normative) ✓.

Canvas placement block

canvas_object    = Assignment
title            = "Week 6 Assignment — Consumer & Producer Surplus & Efficiency (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. Kessler's edition · Fall 2026 · built with thecoursemaker.com"

Traditional variant — for comparison. This course is configured adaptive learning, so the actual Week-6 assignment is the AI-coached version in I-assignment-and-rubric-week-06.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 Microeconomics (ECON 1) · Silver Oak University (fictional sample) · Prof. Kessler
Objective 4 · SLO A & B · Assignment 6 of 14 · 100 points · Due Sun, Oct 11

The Assignment

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

Problem 1 — Find equilibrium (25 pts). A market has demand P = 18 − Q and supply P = 2 + Q.
(a) Solve algebraically for the equilibrium price P* and quantity Q*.
(b) Verify: plug Q* back into both equations and confirm they give the same P.

Problem 2 — Compute consumer surplus (25 pts). Using the market from Problem 1 (P* = 10, Q* = 8, demand P = 18 − Q):
(a) In words, state which region of the supply-and-demand diagram represents consumer surplus.
(b) Compute CS using CS = ½ × Q* × (demand intercept − P*). Show all steps.

Problem 3 — Compute PS and total surplus (25 pts). Still using the same market (P* = 10, Q* = 8, supply P = 2 + Q):
(a) Compute PS using PS = ½ × Q* × (P* − supply intercept). Show all steps.
(b) Compute total surplus (TS = CS + PS), using PS from (a) and CS = 32 from Problem 2.
(c) In one sentence, explain what "allocative efficiency" means in the context of this market.

Problem 4 — Efficiency vs. equity reasoning (25 pts). Consider two claims:
(A) "In the competitive equilibrium, total surplus is maximized."
(B) "Because total surplus is maximized, the market outcome is fair to both buyers and sellers."

In 3–5 sentences: (a) classify each claim as positive or normative and explain why; (b) do you agree that (A) implies (B)? Identify the gap in logic — or make the case that it does imply (B) — using the positive-vs.-normative distinction. A strong answer considers what someone on the other side would argue.

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: Set 18 − Q = 2 + Q → 16 = 2Q → Q* = 8. P* = 18 − 8 = 10. Verify: supply 2 + 8 = 10 ✓. (Numbers pre-computed/verified.)
• P2: (a) CS = the area under the demand curve and above the price line P* = 10, from Q = 0 to Q* = 8. (b) Demand intercept (Q = 0): P = 18. CS = ½ × 8 × (18 − 10) = ½ × 8 × 8 = 32. (Verified.)
• P3: (a) Supply intercept (Q = 0): P = 2. PS = ½ × 8 × (10 − 2) = ½ × 8 × 8 = 32. (b) TS = 32 + 32 = 64. (c) Allocative efficiency: the equilibrium maximizes total surplus — every mutually beneficial trade occurs and no value is lost. (Verified.)
• P4: (a) Claim A = positive (model-derived, testable). Claim B = normative ("fair" is a value judgment). (b) A does NOT imply B: efficiency tells us the pie is as large as possible, not that its division is just. The split of CS and PS depends on elasticities, not fairness. The counterargument — "voluntary trade is consensual, so it's fair" — is worth engaging: it's a normative premise (that voluntariness implies justice) not a positive result. Either side earns full credit if the positive/normative distinction is explicit and the reasoning is evenhanded.

Quality gate (self-checked): P1 (18 − Q = 2 + Q → Q=8, P=10, verify ✓); P2 (demand intercept 18, CS = ½×8×8 = 32 ✓); P3 (PS = ½×8×8 = 32, TS = 64 ✓); P4 (A positive, B normative, efficiency ≠ fairness — curve-logic and surplus-area direction checked ✓). No invented statistics or data.

Canvas placement block

canvas_object    = Assignment
title            = "Week 6 Assignment — Consumer & Producer Surplus & Efficiency (traditional)"
assignment_group = "Assignments"
points_possible  = 100
grading_type     = points
submission_types = [online_upload, online_text_entry]
due_offset_days  = 6
rubric_ref       = "w06-assignment-rubric"
published        = true
provenance       = "~ Prof. Kessler's edition · Fall 2026 · built with thecoursemaker.com"