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This recap covers the last 37 minutes of the September 17 class, the first session on Markets and Coordination (the first half of that period finished Gains from Exchange; its pages are in the Lecture 4 module). Class delivered the coordination puzzle, the full price and the egg table, the taxi-license cap, the three functions of a price, and the four-buyer car table up to the price at which seven cars clear. Two TopHat items ran. The lecture stopped there and continues Tuesday with the fire that destroys a car, price ceilings, and the words shortage, scarcity, and surplus. Read the four-step diagnostic first. Then use the lecture sections to reconnect each idea to an example from class. Finish with the application checks. The separate transcript has the full explanation, including the pencil, the toaster, the rent-extraction aside, and the platinum railroad.

What you should be able to do

1. Compute a buyer’s full price and a seller’s net receipt from a cash price and the nonmoney costs, and show whether a middleman’s cash price leaves each side better or worse off.
2. Given a rule that restricts entry, name who gains the protected margin, who loses (riders, excluded entrants, forgone trades), and what the lobbying itself costs; use the term rent-seeking correctly.
3. State the three functions of a price and apply them to a price change, distinguishing a movement along a supply curve from a shift of it.
4. Add individual demand schedules into a market demand schedule and find the clearing price for a fixed stock.

Core · From individuals to markets

Millions of people plan the groceries. What coordinates their plans?

So far the course has watched individuals: Sam and Joe in the camp, the newcomer. Now the subject is markets, because that is where we live: cars, homes, stocks, bonds, grocery stores, farmers markets. Walk through Publix and think about the effort behind it: millions, really billions, of people made it possible, and nobody is in charge. Publix is not in charge; it does not produce the food. Leonard Read’s essay “I, Pencil” makes the point with something simpler. The wood needs lumberjacks, who need food that someone else grew; the graphite is mined; the ferrule was brass, which is zinc and copper that someone knows how to mine with machines someone else knows how to build; the eraser is rubber. No one person knows how to make a pencil, and yet pencils sit in Walmart, Target, and the bookstore for twenty cents. (An anthropologist who tried to build a toaster entirely from scratch produced a melting death trap.) The question is how the actions of billions of strangers get coordinated to grow, ship, and sell what people want, in roughly the right amounts and places. It is not a central plan, so the answer must be something else. And the related puzzle: when we tried to run the process by direct control, in the Soviet Union, it worked horribly. Look up the photographs of Boris Yeltsin, later Russia’s president, visiting an ordinary Texas grocery store: astonished, like a caveman shown an iPhone. If a future president reacted that way, imagine an average Russian after the wall came down.

TopHat check: what does a repeatedly empty shelf indicate?

The item: a grocery shelf repeatedly becomes empty even though bakers, shippers, and retailers are making independent decisions. It cannot mean a single planner failed, because the decisions are independent; the participants have not stopped deciding quantities; and the supply is plainly not the right amount, since nobody enjoys empty shelves. It indicates that the participants’ plans were not coordinated closely enough to meet demand. The rest of the topic asks how plans get coordinated that closely.

A middleman can raise the cash price and lower the full cost

Back to middlemen. A used car is listed at $5,000; you could spend weekends searching, do the inspection, and bear the risk of being cheated. Those are transaction costs, the costs of transacting, and the full price of the car is the cash plus all that hassle. Simpler still, an egg. You would pay 8 cents for it, and you spend a cent’s worth of effort finding the rancher who has eggs and judging their quality: full price 9 cents. The rancher would sell for 8 cents but has to find a buyer, market, take the eggs to a farmers market: he receives 8 cents and spends half a cent, netting 7.5. Together the two of you bear 1.5 cents of transaction costs on one egg.

Now a middleman offers to charge you 8.5 cents and to pay the rancher 7.75, each of you doing none of the work. He has turned implicit costs into explicit money costs, and in a way that leaves both sides better off. Ask them and they may deny it: the buyer says he used to pay 8 cents and now pays more, because people often do not think about the full cost of their decisions. But his full price fell from 9 to 8.5, and the rancher’s receipt fell to 7.75 while his net rose from 7.5 to 7.75. The middleman’s spread is 0.75 cents, and it replaced 1.5 cents of transaction costs; the gains from trade grew, exactly as they did when the newcomer arranged Sam and Joe’s deal. This is what Publix does with the ranchers who produce eggs. (In working the numbers aloud the instructor once said 8.25 for the middleman’s price; the slide and the rest of the explanation use 8.5.)

Who gains when the city caps taxi licenses?

The city caps taxi licenses after the existing owners lobby for the cap. Who gains, who loses, and where did the lobbying go? First a definition: what economists mean by an open or free market is that anyone may enter. The market that may appear on exam day for green Scantrons is open, because the instructor puts no restriction on who may sell or at what price. He could instead sell one student an exclusive license to sell Scantrons, auctioned to the highest bidder. That would close the market: entry restricted by force, collusion, or law. Notice who would gain. The licensed student would do well, but the instructor, as the seller of the right, would capture most of the monopoly value in the auction. The same is true of New York taxi medallions: the city and its politicians sell the medallions, which is one reason politicians close markets and then sell access to them.

Effects of the cap, then. Fewer rivals mean higher fares. The license becomes valuable, so owners will pay a lot for one, to capture the higher fares. Higher fares mean fewer rides, by the law of demand, so some gains from trade never happen. And the effort to win the cap is rent-seeking: real resources spent to obtain a favor rather than to produce anything. A colleague’s classroom auction shows how far it goes: put a $20 bill up for bids and the offers climb, one dollar, two dollars, until the bidding stops at about $20 and the whole value of the prize has been dissipated in competing for it. If the exclusive Scantron right were worth $100, free competition to win it would bid $100, the winner would gain little, and the seller of the right would gain the most. A zero-sum transfer at best, minus the resources spent. Freedom of competition means open entry; freedom from competition is protection. Medicine and law are closed markets: the American Medical Association and the American Bar Association moved their professions from freedom of competition to freedom from it.

TopHat check: a city restricts taxi entry after owners lobby for it

The item asked which analysis best explains the economic effects. Nobody chose the claim that existing owners lose while the lobbying directly increases taxi services. The answer: existing owners gain a protected margin while riders face higher costs, forgone rides, and rent-seeking costs, part of which is passed on to the riders themselves.

While the poll ran: rent extraction, R&D credits, and football stadiums

A relative of rent-seeking is rent extraction. Once a protected industry exists, the politician can return: “Nice monopoly privilege you have there; it would be a shame if someone took it away. What will you do for me?” American research-and-development tax credits are not permanent; they come up for a vote every few years, and companies are told each time that the vote will be close (Peter Schweizer’s book Extortion is the reference). Rents created by protection, or by a genuinely new technology, can be extracted the same way. The instructor’s own theory of stadium subsidies follows: even a franchise that buys the land and builds with its own money cannot move the stadium once it stands, so a city could later threaten its zoning; knowing that, the owner would never build. Taxpayer money up front is the only way a city can credibly commit not to expropriate later. It pleases nobody, but it explains the pattern.

The price of eggs doubles overnight. What does that one number do?

Three things. It is a signal: a baker who needs eggs and flour learns to raise prices and produce less bread. It is a reward: ranchers get a better price, and if they can, they produce more eggs. And it rations: by the law of demand people buy fewer eggs, so the eggs that exist go to those who value them most. A student asked whether a rancher would really produce more with no change in technology, wages, or rent. Yes, and the distinction matters: a higher price with no change in the rancher’s costs moves him up a given supply curve, a larger quantity supplied, not an increase in supply, which would be the whole curve shifting (drawn in words, since no marker in the room worked). Prices are both incentives and little pieces of knowledge. Railroad ties could be made of platinum; they are steel because steel is far cheaper per ton, and the price carries that fact to people who know nothing about platinum mining. The Soviet planners had no prices, so they could not sort the technologically possible ways of producing something from the economically sensible ones. Run it in reverse: a study says eggs cause cancer, demand falls, the price falls, fewer eggs are produced, and the falling price tells the rancher to raise fewer hens and switch to other livestock. When output can respond, the higher price gives sellers a reason to provide more; when the stock is fixed, as it always is at a moment in time, the higher price rations the eggs to their highest-valued uses.

Add every buyer’s demand at each price. Seven cars exist. Where do they clear?

Four people, A through D, each with a demand schedule for cars. At $10,000, A wants one, B none (a first car is not worth $10,000 to B), C one, D one. At $1,000, A wants four; by the law of demand, the marginal value of A’s fourth car is $1,000, because people buy up to the point where the value of the last unit just equals the price. B wants four, C two, D four. To go from individual demand to market demand you add them up at each price: 3 cars at $10,000, 14 at $1,000. To know where the market clears you need one more fact, the supply: how many cars exist. Seven, all alike, none can be built. Then the price that emerges is $7,000, because at $7,000 A wants two, B one, C two, D two, seven in all. (A student answered $49,000, which is total revenue, seven cars at $7,000; the clearing price is per car.) Given a demand schedule and the number of cars, you can read off the price. Class stopped there: “we’ll wrap this up on Tuesday.”

What continues Tuesday

The lecture resumes at the seven-car market. Coming: what a rising price does when the stock cannot grow; a fire destroys one of A’s two cars and the price rises to $8,000, so A buys C’s second car and both gain; what happens instead if a price ceiling is imposed before that sale; and the difference between scarcity, a reduction in supply, a shortage, and a surplus. Then the topic’s recap and, as time allows, the applications. As time allows, Tuesday may also include instructor-led practice on exam items from the first four topics. The TA’s review is Thursday, September 24, and Exam 1 is Tuesday, September 29 (green Scantron, pencil, calculator allowed, open note). Tuesday’s class gets its own recap and transcript page.

Examples are memory cues; the right column is the principle each example should help you recover.

Example from class	Economic lesson
“I, Pencil”: lumberjacks, graphite, zinc and copper, rubber	No one holds the knowledge to make even a pencil; the knowledge is dispersed and coordinated without a planner.
The from-scratch toaster that melted	What one person can do alone is a death trap; the market’s product is cheap and works because of division of knowledge.
Boris Yeltsin in a Texas grocery store	The one large experiment in replacing prices with central control produced empty shelves; the puzzle is why.
The empty shelf despite independent decisions	Coordination failure means plans did not mesh closely enough with demand, not that someone stopped deciding.
The $5,000 used car and the weekends spent searching	Full price = cash + transaction costs; the sticker is not the price.
The egg: 8 + 1 = 9 for the buyer; 8 − 0.5 = 7.5 for the rancher	Both sides of a do-it-yourself trade pay in trouble; here 1.5 cents of the trade is eaten.
The middleman charges 8.5 and pays 7.75	A higher cash price can be a lower full price; judge the middleman by full prices and both sides gain.
“I used to pay 8 cents and now I pay more”	People compare cash prices and miss the full cost; that is why middlemen get blamed for the work they remove.
Selling one student the exclusive right to sell green Scantrons	Closing a market creates a protected margin, and the seller of the privilege captures most of its value.
The $20 bill auctioned in class	Competing to capture a fixed prize dissipates its value; rent-seeking spends real resources for a transfer.
Higher fares, fewer rides	The law of demand means a closed market forgoes trades that would have happened; that loss is not a transfer.
“Nice monopoly privilege; it would be a shame if…”; R&D credits that expire	Rent extraction: politicians threaten existing rents to collect payments; protection creates the target.
Taxpayer-funded stadiums	A subsidy can be the only credible commitment against later expropriation of an immobile investment.
The baker, the rancher, and the shopper when eggs double	A price is a signal (use less), a reward (make more), and a rationing rule (who gets what exists).
Producing more eggs with no change in costs or technology	A movement along the supply curve (quantity supplied), not a shift of supply.
Platinum railroad ties	Prices carry knowledge about relative scarcity and attach an incentive to act on it; planners without prices cannot choose among feasible methods.
“Eggs cause cancer”	A fall in demand lowers the price, which tells producers to make less; the price moved first, not the supply.
A wants four cars at $1,000	Each buyer stops where the marginal value of the last unit equals the price.
3 at $10,000, 14 at $1,000, 7 at $7,000	Market demand is the sum of individual demands at each price; the market clears where the sum equals the stock.
The student who answered $49,000	Price times quantity is total revenue; the clearing price is the per-unit price where amount wanted equals amount available.

Question 1 — A textbook sells for $60 at the campus store, ten minutes away, and for $52 online, where you spend an hour comparing listings, pay $6 shipping, and wait a week. Which is cheaper?

It depends on the full price, not the sticker. The online book costs $58 in cash plus an hour of your time and a week’s wait; the store costs $60 plus ten minutes. For someone whose time is worth little the online book is cheaper; for someone in a hurry the store is. The store is a middleman selling you the finding, checking, and waiting.

Question 2 — A rancher says the egg middleman “takes three-quarters of a cent from every egg for doing nothing.” What did he do, and is the rancher worse off?

He removed the rancher’s half-cent of selling cost and the buyer’s cent of searching cost, 1.5 cents in all, and replaced them with a 0.75-cent spread. The rancher receives 7.75 instead of netting 7.5; he is a quarter of a cent better off per egg, and the buyer half a cent. The spread pays for work that no longer has to be done twice over by amateurs.

Question 3 — A city announces it will auction 200 new taxi medallions to the highest bidders. Who ends up with the monopoly gains from restricted entry?

Mostly the city. Bidders compete for the protected margin until the medallion price roughly equals the value of the higher fares, as with the $20 bill in class, so the buyers earn close to a normal return and the seller of the privilege collects the value. Riders still pay the higher fares and lose the forgone rides; the bidding is rent-seeking.

Question 4 — “Capping licenses transfers money from riders to owners, so it is a wash for society.” What is missing?

Two real losses on top of the transfer: the rides that no longer happen at the higher fare (gains from trade forgone, by the law of demand) and the resources spent lobbying for and defending the cap. A transfer moves wealth; these destroy it.

Question 5 — A frost destroys half of Florida’s orange crop and the price of orange juice jumps. Name the three things the higher price does, and say who ends up with the juice.

Signal: buyers and juice makers learn oranges are scarcer and economize. Reward: growers elsewhere, and Florida growers next season, have a reason to supply more. Rationing: with a fixed stock this season, the juice goes to those willing to give up the most for it, not necessarily those who “need” it most. Willingness and ability to pay is the rule.

Question 6 — A classmate says a higher egg price “increases supply.” Correct the wording.

With no change in the rancher’s costs or technology, a higher price raises the quantity supplied, a movement along the existing supply curve. An increase in supply is a shift of the whole curve, caused by something other than the price of eggs, such as cheaper feed or better hens.

Question 7 — Three buyers want, at each price, the following number of bikes: at $300: 1, 0, 1; at $200: 2, 1, 1; at $100: 2, 2, 2. Four bikes exist and none can be built. Where does the market clear, and what can you say about the value of the second buyer’s first bike?

Sum across each row: 2 bikes wanted at $300, 4 at $200, 6 at $100. The market clears at $200, where the four wanted equal the four that exist; at $300 two bikes would go unsold and at $100 six are wanted. The second buyer wants no bike at $300 and one at $200, so his first bike is worth at least $200 and less than $300 to him, the same reading the instructor gave for A’s fourth car at $1,000.

Question 8 — Why did the instructor call the $49,000 answer “total revenue” rather than wrong?

Seven cars at $7,000 each is $49,000, which is what the sellers collect in total. The question asked for the clearing price, a per-car number: the price at which the amount the four buyers want equals the seven cars that exist. Keep the two apart; price times quantity returns in producer theory.

Bottom line

Billions of strangers’ plans get coordinated without anyone in charge, and the attempt to replace that with a plan failed badly. The coordination runs on full prices. A middleman who raises the cash price can lower the full price and leave both sides better off, which is what Publix does between you and the ranchers. Close a market and the insiders gain a protected margin, riders lose rides, and real resources are burned winning the favor, often to the benefit of whoever sells it. A price signals, rewards, and rations, and it does so because it is knowledge with an incentive attached. Add up what every buyer wants at each price and the market clears where that sum equals what exists: seven cars at $7,000. Tuesday: a fire, a ceiling, and why a shortage is not the same as scarcity.