What was the question for this implicit rationale, and corresponding answer?
This is the relevant information: A deadweight loss, also known as excess burden or allocative inefficiency, is a loss of economic efficiency that can occur when equilibrium for a good or a service is not achieved.
The answer: economic efficiency
The question: A deadweight loss, also known as excess burden or allocative inefficiency, is a loss of economic efficiency that can occur when equilibrium for a good or a service is not achieved. That can be caused by monopoly pricing in the case of artificial scarcity, an externality, a tax or subsidy, or a binding price ceiling or price floor such as a minimum wage.

Answer this question: deadweight loss measures the inefficiency as the loss of?