Interactive teaching tool
Supply & demand, by hand
Grab a curve and pull it. Grab the price and drag it off the crossing. Prices, quantities and the pile of stock nobody bought all answer while your finger is still moving — which is the fastest way there is to find out what these two lines actually mean.
- Drag a curve sidewaysThat is a shift: more buyers, fewer mills. Watch where the crossing goes.
- Drag the price tagPin it below the crossing and a shortage opens. Above it, a pile.
- Change the steepnessSteep curves throw the shock into price. Flat ones throw it into quantity.
Drag the curves sideways. Drag the price tag up or down to pin a price and watch the gap open. Everything answers as you move.
Price$450— unchanged
Actually traded4,500 MBF— unchanged
Market clearsCleared. Every unit offered found a buyer, and every buyer willing to pay this much got one.
Builders want
Mills offer
One block ≈ 375 MBF. Every block offered has a buyer.
Price is free, so it sits where the two curves cross. Drag the price tag to pin it — a rent cap, a minimum wage, a price gouging law — and the gap appears.