Specialisation, the division of labour and money

Specialisation is the concentration of a worker, firm, region or country on a narrow range of tasks. The division of labour (Adam Smith's pin factory, 1776) breaks production into repeated tasks. Ten pin-makers working alone might make 200 pins a day; divided into eighteen distinct operations, Smith reported, they made 48,000.

• Advantages: workers get faster at a repeated task; time is not lost switching jobs; training is cheaper and narrower; it makes specialist capital worth buying; output per worker (productivity) rises, so unit costs fall.
• Disadvantages: repetitive work is demotivating (higher absenteeism and turnover); workers become occupationally immobile — a redundant specialist may have no other marketable skill; a break anywhere in the chain halts everything (interdependence); mass-produced goods can lack variety.

Specialisation only pays if you can trade the surplus. In a barter system that requires a double coincidence of wants — I have fish, you have shoes, and you must happen to want fish right now. Money removes that constraint by acting as a medium of exchange (as well as a store of value, unit of account and standard of deferred payment). Money is therefore not a luxury bolted onto the economy; it is what makes specialisation, and hence modern productivity, possible.

Why does specialisation need money?

Demand: movements and shifts

Demand = the quantity consumers are willing and able to buy at each price in a given period (willingness alone is a wish, not demand). The demand curve slopes downward for two reasons:

• Income effect — a price fall raises real income, so more can be bought.
• Substitution effect — the good is now relatively cheaper than its substitutes, so consumers switch to it.

Underneath sits diminishing marginal utility: each extra unit gives less added satisfaction, so consumers will only buy more if the price falls.

Market demand is the horizontal sum of all individual demand curves at each price.

The distinction examiners hammer: a change in the good's own price causes a movement along the curve (an extension or contraction). A change in anything else — income, the price of substitutes or complements, tastes, population, expectations, advertising, interest rates — shifts the whole curve.

Three demand relationships OCR names explicitly:

• Joint (complementary) demand — goods bought together: printers and ink.
• Competitive demand (substitutes) — goods bought instead of each other: butter and margarine.
• Composite demand — one good demanded for two competing uses: milk for cheese or for drinking, so more cheese-making raises the price of drinking milk.

Movement or shift?

Supply and the interaction of markets

Supply = the quantity producers are willing and able to sell at each price. The supply curve slopes upward because a higher price (a) makes output more profitable, so existing firms expand, and (b) covers the rising marginal cost of extra output (the law of diminishing returns), and (c) attracts new firms into the market.

A change in the good's own price = a movement along (extension/contraction). Shifters of supply: costs of production (wages, raw materials, energy), technology, productivity, indirect taxes and subsidies, the number of firms, weather/shocks, and the price of goods in joint or competitive supply.

• Joint supply — producing one good automatically produces another: beef and leather; oil and gas.
• Competitive supply — a producer can make A or B with the same resources: a farmer's field grows wheat or barley.

Equilibrium is where D = S: the market clears and there is no tendency to change. Above it there is excess supply (a surplus), so unsold stock forces the price down; below it there is excess demand (a shortage), so buyers bid the price up. Markets are analysed ceteris paribus — "other things being equal" — because we can only isolate one cause at a time.

Interconnection: a fall in the wheat harvest raises the price of wheat → raises the cost of bread (a derived demand for wheat) → raises demand for the substitute, rice → raises the price of rice. Markets are never isolated.

Solving for equilibrium

You will be given demand and supply as equations. Set them equal and solve.

Now do the same for a different market on the next screen. Keep the same method: set the two expressions for P equal, solve for Q, substitute back for P.

Your turn — equilibrium price

Your turn — equilibrium quantity

Consumer and producer surplus

The demand curve is a willingness-to-pay curve; the supply curve is a willingness-to-accept curve. The gaps between them and the market price are the gains from trade.

• Consumer surplus = the difference between what consumers would have been willing to pay and what they actually pay. It is the triangle below the demand curve and above the price.
• Producer surplus = the difference between the price received and the minimum the producer would have accepted. It is the triangle above the supply curve and below the price.

Evaluation point: a price rise shrinks consumer surplus and (usually) raises producer surplus — a transfer from buyers to sellers plus a loss of the trades that no longer happen. This is exactly the machinery you will use later for taxes, subsidies and monopoly.

Your turn — consumer surplus

Your turn — producer surplus

The three functions of price

Hayek's insight: a price is a compressed packet of information. When a tin mine collapses, no one needs to know why — the rising price tells every user of tin, everywhere, to economise, and every producer to dig more. The price mechanism performs three functions at once:

• Signalling — prices convey information about relative scarcity, telling buyers and sellers where resources should flow.
• Incentive — a higher price raises profitability, rewarding firms that expand output and enter the market (and punishing those who stay in a shrinking one).
• Rationing — when a good is scarce, a rising price restricts it to those willing and able to pay most, eliminating the shortage.

Put together, these give consumer sovereignty: consumers vote with money, firms chase the profit, and resources are reallocated without anyone ordering it. This is Adam Smith's invisible hand.

Evaluate it: rationing by price is efficient but not necessarily equitable — it rations by ability to pay, so during a shortage the rich get the insulin. And the mechanism only delivers allocative efficiency when prices reflect full social costs and benefits, which is exactly what externalities and public goods destroy. That is the bridge to market failure.

Which function of price?

Composite demand

Disequilibrium

Shift or movement?

Tap a card, then tap what it does to the market for the good.

Match the term to its meaning

Tap an item on the left, then its partner on the right.

The big ideas to know

You've now covered demand, supply and the price mechanism from the OCR A-level Economics (H460) specification. Press Finish to see your score.