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Week 1 · Lecture outline

Week 1 — Lecture Outline · The Macro Perspective: Scarcity, the PPF, Circular Flow & Economic Models

Principles of Macroeconomics · ECON 2 Fall 2026 · Prof. Ashford Fictional sample

Course: Principles of Macroeconomics (ECON 2) · Silver Oak University (fictional sample) · Prof. Ashford
Objective 1 — macroeconomic modeling & quantitative/graphical analysis; scarcity, opportunity cost, the PPF, the circular flow; positive vs. normative · SLO A & B
Meeting pattern: two 75-min sessions (≈150 min). Segment minutes below total ~150 — scale to your room.

The deck (E), the tutorial (C), and the workshop (P) all teach from this outline. Every number here is pre-computed and independently verified (see the verified box in §4).

Week at a glance
Big question What does macroeconomics actually study, and how do economists model an entire economy's choices?
By week's end students can (1) define macroeconomics and distinguish it from microeconomics; (2) compute opportunity cost in goods and dollars; (3) read an economy-scale PPF — slope = opportunity cost, bowed shape, efficient/inefficient/unattainable points, and the macro reading of an interior point (idle resources); (4) describe the circular-flow model in plain terms; (5) tell a positive statement from a normative one.
Key vocabulary macroeconomics vs. microeconomics, scarcity, opportunity cost, trade-off, model, ceteris paribus, production possibilities frontier (PPF), consumer goods vs. capital goods, efficient/inefficient/unattainable, increasing opportunity cost, circular-flow model, product markets, factor markets, positive vs. normative
Materials whiteboard; the Week-1 readings/links; Desmos or a spreadsheet for the PPF; an approved chatbot
Timing note 8 segments ≈ 150 min across two sessions. Trim Segment 7 (interaction) if short on time.

Segment 1 — HOOK: "Is the economy doing well?" (12 min)

Open by asking the room: "Is the economy doing well right now?" Let a few answers land — someone will mention prices, someone jobs, someone the stock market. Then the reframe: "Notice what just happened — you all reached for different NUMBERS. By the end of this course, you'll be able to answer that question with actual tools: growth, inflation, unemployment, and the policies that move them. That's macroeconomics."

Draw the line the whole course rests on: microeconomics zooms in on individual choosers — one household, one firm, one market (that's a different course). Macroeconomics zooms out — it studies the economy as a whole: total output, the overall price level, the nation's job market, and the policy tools (fiscal and monetary) that try to steer all of it. Same underlying idea — scarcity forces choice — but now the "chooser" is an entire economy of millions of households and firms acting at once.

Segment 2 — PLAIN-LANGUAGE IDEA: scarcity & opportunity cost, at any scale (18 min)

Teach it in one sentence first, then formalize:

Opportunity cost = the value of the next-best alternative given up when a choice is made — whether the "chooser" is one person or an entire economy.

Plain-language build: there is never enough — not enough labor-hours, factories, farmland, or raw materials — to produce everything everyone wants. That's scarcity, and it forces choice at every scale, from a single Saturday afternoon to a national budget. Macroeconomics asks the same question — "what did we give up to get this?" — but about GDP, jobs, and government budgets instead of one person's time.

Two quick, concrete reads (no math yet):
- A country that pours resources into building factories today gives up consumer goods it could have produced right now — the classic "guns vs. butter" trade-off, at a national scale.
- A government that spends a dollar on infrastructure has, at that moment, given up spending that same dollar somewhere else — schools, defense, a tax cut.

Memory hook: "There's no such thing as a free lunch — for a person, a firm, or a whole economy." Someone, somewhere, gives something up.

Introduce three lenses we'll use all term (name them now, use them weekly): zoom out to the whole economy (not one buyer or seller), track stocks vs. flows and short run vs. long run (a recurring macro habit), and separate positive from normative (what the model predicts vs. what we should do about it).

Segment 3 — WORKED EXAMPLE #1: opportunity cost in dollars (15 min)

Set it up on the board and do every step out loud.

A student has a 5-hour free block this evening. They could work a job that pays $18/hour, or spend the time however they like.

  • If the student works all 5 hours: they earn 5 × $18 = $90.
  • If the student instead takes the evening off, the opportunity cost of that free time = $90 — the money they gave up.
  • Flip it: if they value the evening off at more than $90, taking it off is the better choice; if less, they should work. The decision rule is a comparison of opportunity costs — the same rule that will later explain why a whole economy chooses more consumer goods vs. more capital goods.

Say it in words (this is the SLO-A habit): "The free evening 'costs' $90 — that's not a fee paid, it's income forgone." Forgone benefits are real costs, whether the decision-maker is one student or a national government.

Segment 4 — THE PPF: the model that shows scarcity for an ENTIRE ECONOMY (28 min)

Now the week's centerpiece graph — the same PPF idea from Segment 2's opening, but built for a whole economy rather than one person's afternoon. The production possibilities frontier (PPF) shows the maximum combinations of two goods an economy can produce with fixed resources (labor, capital, land) and technology.

Build the model from a scenario (described-graph walkthrough — draw it as you go):

The fictional economy of Isla Verde has 24 million labor-hours available this period. Producing one unit of consumer goods (x) takes 3 hours; producing one unit of capital goods (y) takes 6 hours.

  • All 24 million hours on consumer goods → 24 ÷ 3 = 8 units of consumer goods, 0 capital goods → plot point (8, 0).
  • All 24 million hours on capital goods → 24 ÷ 6 = 0 consumer goods, 4 units of capital goods → plot point (0, 4).
  • Connect them. Because the trade-off here is constant, this PPF is a straight line: 3x + 6y = 24.

✅ VERIFIED NUMBERS (pre-computed; do not recompute live)

  • Endpoints: (8, 0) and (0, 4).
  • Slope = opportunity cost. Moving from (8,0) toward (0,4): give up 8 units of consumer goods to gain 4 units of capital goods → 1 capital good costs 2 consumer goods; equivalently 1 consumer good costs ½ a capital good.
  • Test (4, 2): 3(4) + 6(2) = 24 → on the frontier (efficient). Test (2, 2): 3(2) + 6(2) = 18 < 24 → inside (inefficient — idle labor-hours). Test (6, 3): 3(6) + 6(3) = 36 > 24 → outside (unattainable — not enough labor-hours exist).

Read the graph out loud (the four things a PPF shows at once) — now at the scale of a whole economy:
1. Scarcity — Isla Verde cannot produce outside the frontier; only 24 million labor-hours exist.
2. Trade-offs — to get more capital goods, the economy slides down the line and produces fewer consumer goods.
3. Opportunity cost — the slope is exactly how many consumer goods each capital good costs the whole economy.
4. Efficiency — points on the frontier use every resource; points inside waste some.

The macro twist (this is what makes it macro, not micro): a point like (2, 2) — inside the frontier — is not just "one firm being inefficient." At the scale of an entire economy, an interior point means idle labor and capital sitting unused — in other words, unemployment. This is your first preview of a recession: the economy has the resources to produce more of both goods, but for some reason (we'll build the model for "why" starting in Week 5) it isn't. And the choice of where along the frontier to sit — more consumer goods today, or more capital goods (factories, equipment, infrastructure) — is a preview of Week 4's growth story: more capital goods now means the frontier itself can push outward faster later.

Why real economies' PPFs bow outward (increasing opportunity cost): resources aren't equally good at everything. As an economy pushes all-in on one good, it has to pull over resources that were lousy at it, so each extra unit costs more and more of the other good. That's why a realistic PPF is bowed out (concave), and the slope gets steeper as output shifts along it. (Our straight-line Isla Verde example is the simplified constant-cost case; show both.)

Segment 5 — THE CIRCULAR-FLOW MODEL & POSITIVE vs. NORMATIVE (15 min)

The circular-flow model is macro's second core picture — a simplified map of how money and goods move through the whole economy. Two groups, two markets:

  • Households supply labor and other resources and demand goods/services.
  • Firms demand labor and other resources and supply goods/services.
  • They meet in product markets (where firms sell goods and services to households) and factor markets (where households sell their labor, capital, and land to firms).

Describe the loop out loud: households earn income in factor markets → spend it in product markets → firms collect that revenue → pay it back out to households as wages, rent, and profit in factor markets → and the loop repeats. Preview, qualitatively only (we'll build the numbers starting Week 2): money doesn't just circle forever — some of it leaks out (saving, taxes, spending on imports) and some flows back in (investment, government spending, spending on exports) — the leakage/injection idea that sets up the whole rest of the course's arc from measurement to policy.

Positive vs. normative — the second tool of the week, and one that prevents most bad macro arguments:

  • Positive economics — descriptive, testable claims about what is: "Unemployment is 5% this quarter." Could be right or wrong, but it's about facts.
  • Normative economics — value judgments about what ought to be: "The government should prioritize lowering unemployment over fighting inflation." No data settles a should.

Drill (rapid-fire, thumbs up/down): classify each — "GDP grew 3% last quarter" (positive), "Growth should be the government's top priority" (normative), "Unemployment is 5%" (positive), "Unemployment is too high" (normative). Misconception to kill: "positive = good, normative = bad." No — positive means factual, normative means value-laden. Both matter; good policy needs both, but you must know which is which.

Segment 6 — TECHNOLOGY WORKFLOW + AI-CRITIQUE (20 min)

Live demo (Desmos or spreadsheet): plot Isla Verde's PPF by graphing the line 3x + 6y = 24 (x = consumer goods, y = capital goods). Drag a point along it to show the trade-off; mark an interior point (idle resources) and an exterior point (unattainable).

AI-critique moment (do this with the class): Ask an approved chatbot: "For an economy with 24 million labor-hours, where consumer goods take 3 hours each and capital goods take 6 hours each, what is the opportunity cost of one capital good? Is the point (6, 3) attainable?" Then audit it together: the right answers are 2 consumer goods for the opportunity cost, and NO — (6, 3) is unattainable (3·6 + 6·3 = 36 > 24). Chatbots frequently flip the ratio (say "½ a consumer good"), or wave through an unattainable point without checking the equation, or confuse "inside the frontier" (idle resources) with "outside the frontier" (impossible). Make the class catch the error and state the correct reasoning. The habit all term: the tool drafts, you judge.

Segment 7 — INTERACTION: think-pair-share (12 min)

Pose: "A news headline says 'The economy grew 3% and unemployment fell to 4%.' A second headline says 'The government should have grown the economy faster.' Which one is macroeconomics measuring, and which one is a value judgment?" Pairs argue, then share. Target answer: the first headline is positive (a testable measurement); the second is normative (a judgment about priorities). This previews Discussion 1 directly — separating what the economy is doing from what we think it should do.

Segment 8 — CALLBACKS, TEASE & THE WEEK'S WORK (10 min)

  • Callback: every example today shared one engine — scarcity forces a trade-off at any scale, and macroeconomics studies that trade-off for the whole economy at once.
  • Tease next week: "If we're going to talk about 'the economy' as one thing, we need a number for its size. Next week: Gross Domestic Product — how economists add up an entire economy's output, and why 'real' and 'nominal' are two very different numbers."
  • The week's work: Lecture Tutorial (macro vs. micro → opportunity cost → the PPF → the circular flow → positive/normative), Practice (6 reps), Quiz 1, Discussion 1, Assignment 1, and Workshop 1 (build an economy's PPF on Desmos and read its opportunity costs).

Instructor FAQ — common stumbles

  • "Isn't macro just 'big micro'?" No — it asks different questions (growth, inflation, unemployment, policy for the whole economy) and uses some tools micro doesn't need (aggregate measures, the circular flow, national policy). There's also a real logical trap here: something true for one saver isn't automatically true for everyone saving at once — the fallacy of composition. (Example: one household saving more helps that household, but if every household saves more at the same time, total spending can fall — a dynamic some Keynesian economists call the paradox of thrift, named here factually as an idea in that tradition, not settled doctrine.)
  • "A point inside the PPF is unattainable, right?" No — it's inefficient/idle (resources sitting unused, like unemployment), not impossible. Unattainable points are outside the frontier.
  • "Positive vs. normative — which is 'better'?" Trick framing. Positive = factual/testable; normative = value judgment. Neither is "better"; mixing them up is the error.
  • "Why is the PPF a curve and not a line?" Increasing opportunity cost: resources are specialized, so each extra unit of one good costs more of the other. The straight-line case (constant cost) is the simplified version; real frontiers bow out.
  • "Slope vs. opportunity cost?" On a PPF they're the same thing: the slope's magnitude is the opportunity cost of the good on the x-axis (in units of the y-axis good). Watch which good is which.
  • "What's the circular flow actually for?" It's the map we'll keep returning to: GDP (Week 2) is just a way of measuring the flow through the product-market side; fiscal and monetary policy (Weeks 7–11) work by nudging the flow's leakages and injections.

~ Prof. Ashford's edition · Fall 2026 · built with thecoursemaker.com