在經濟學，什麼是供不應求？

這是指物品的價格低於 市場均衡價格 因此造成超額需求的問題(即是你所指的供不應求) 所以這物品的價格有上調的拉力..最後造成供需平衡..除非政府作出市場干預..不讓價格上升 eg: 設定價格上限

The quantity demanded is greater than the quantity supplied, it is called excess demand.It occurs when the price is set below the equilibrium price. Since the price is too low, people tend to buy more, however, the quantity of goods that producers prodeuced is not enough. Therefore, the price tends to rise to solve the problem-excess demand.

the quantity of demand is larger than the quantity of supply.