When the price of a good is set too low, it creates a situation known as a shortage. This occurs when the quantity demanded exceeds the quantity supplied, meaning consumers want to purchase more of the product than suppliers are willing to produce at that price. For instance, if the equilibrium price is $6 and the price is lowered to $4, we can analyze the effects on supply and demand.

In this scenario, at a price of $4, suppliers are willing to provide only 6 units of the product. However, the demand at this lower price is significantly higher, with consumers wanting 15 units. This discrepancy indicates that the market is not in equilibrium, as the quantity supplied (6 units) is less than the quantity demanded (15 units).

The shortage can be quantified by subtracting the quantity supplied from the quantity demanded. In this case, the shortage is calculated as follows:

Shortage = Quantity Demanded - Quantity Supplied = 15 units - 6 units = 9 units.

This 9-unit shortage highlights the imbalance in the market, where consumers are eager to buy more than what is available at the low price. Understanding this concept is crucial for grasping the law of supply and demand, which illustrates how prices adjust to reach equilibrium in a market.