Shortage

What Is Shortage?

A shortage, or excess demand, exists when the quantity buyers wish to purchase exceeds the quantity producers offer at the prevailing price. It arises whenever the market price sits below the equilibrium price. With more buyers than available goods, competition among consumers pushes the price up. In an unregulated competitive market, the rising price both discourages some buyers and draws out more supply until quantity demanded equals quantity supplied and the market clears. A shortage can also be sustained by policy: a binding price ceiling set below equilibrium, such as rent control on apartments, holds the price too low to clear the market and causes a persistent shortage.

Why It Matters

Shortages show why prices matter as signals and what goes wrong when they are suppressed. A temporary shortage is self-correcting: rising prices ration the good to those who value it most while encouraging more production. But when a price ceiling holds the price below equilibrium, the shortage never clears. The classic example is rent control, which leaves more people seeking apartments than are available. Understanding shortages helps explain empty shelves after price freezes, long queues, and the black markets that can follow. It also reinforces the equilibrium benchmark: markets left to adjust eliminate shortages on their own, whereas well-intentioned price caps can lock them in place, often hurting the very buyers they aim to help.

Test Your Knowledge

Questions on this topic from the EconRecall fact bank:

• When the market price sits below the equilibrium price, what condition results?
  A shortage, because quantity demanded exceeds quantity supplied
• A price ceiling is binding only when it is set where relative to equilibrium, and what does it cause?
  Below the equilibrium price, causing a persistent shortage