In economics, a shortage occurs when quantity demanded exceeds quantity supplied at a given price.
Shortages commonly arise when a price is held below the market-clearing equilibrium price. At that lower price, consumers want to buy more, while producers are willing to sell less, leaving some buyers unable to obtain the product. A shortage can also result from a sudden fall in supply, such as a natural disaster or a production disruption.
Shortages may lead to queues, waiting lists, rationing, purchase limits, or unofficial resale markets. These responses do not remove the underlying imbalance; they determine who obtains the limited goods. A shortage differs from a surplus, in which sellers offer more than buyers want at the prevailing price. In a competitive market without restrictions, upward pressure on price usually reduces quantity demanded and increases quantity supplied, helping restore equilibrium.