What defines market equilibrium?

Market equilibrium is defined as the point where quantity demanded equals quantity supplied. This concept is central to economic theory and indicates a state where the market is perfectly balanced — buyers are willing to purchase the exact quantity of goods that sellers are willing to sell at a specific price. At this equilibrium point, there is no surplus of goods (where supply exceeds demand) and no shortage (where demand exceeds supply), leading to a stable market environment.

In practical terms, when the market reaches equilibrium, both consumers and producers are satisfied: consumers can purchase the goods they want at a price that reflects their value, while producers can sell all their products without having excess inventory. This balance is essential for long-term market efficiency and helps in determining the optimal price for goods and services in a competitive market.

The other responses do not capture the essential characteristic of market equilibrium effectively. Total supply equaling total cost does not signify a balanced market; instead, it relates more to producer cost structures. Producers maximizing profits might occur at equilibrium, but that aspect alone doesn't define the equilibrium itself. Lastly, a price at which no goods are sold implies market failure or extreme conditions that are not relevant to the concept of equilibrium in a functioning market.