Which term best describes a situation where total demand equals half the total supply in the economy?

The situation where total demand equals half the total supply in the economy is best described as a demand shortfall. This occurs when the amount of goods and services that consumers want to purchase is significantly less than what is available in the market, leading to an imbalance. In this specific case, since demand is only half of the total supply, it clearly indicates that the demand is lacking compared to what is being produced and offered.

The term "equilibrium level" refers to a state where total demand perfectly matches total supply, meaning there isn’t any surplus or shortage of goods and services. Therefore, it would not accurately describe a scenario where demand is less than supply.

A "recession period" typically signifies a broader economic downturn characterized by a decrease in economic activity, which often includes decreases in demand among other factors. However, it doesn’t specifically address the relationship between demand and supply in terms of their quantitative balance.

"Transient imbalance" might imply a short-term situation where demand and supply do not match, but it lacks the specificity of describing the nature of the shortfall quantitatively. In contrast, the term "demand shortfall" clearly illustrates the disparity observed in the scenario presented.