What is deadweight loss and when can it occur in resource allocation?

• A. A decrease in total welfare from government spending on public goods.
• B. The loss of total welfare from market inefficiency due to taxes, subsidies, price controls, or externalities.
• C. A gain in welfare from perfectly competitive markets.
• D. An increase in producer surplus without changing consumer surplus.

Answer: (B)

Deadweight loss is the reduction in total welfare that occurs when resources are not allocated efficiently, so the gains from trades that would have happened at the efficient quantity are not realized. In a perfectly competitive market without distortions, consumer and producer surplus are maximized at the equilibrium quantity. When taxes, subsidies, price controls, or externalities distort prices, the market moves away from that efficient point, creating a triangle of lost welfare—the deadweight loss. Some of the loss is offset by government revenue from taxes, but there remains a net loss to society from trades that no longer occur or from trades that don’t reflect true costs and benefits. This is why the term describes a loss of total welfare rather than a gain. The other options describe scenarios not about deadweight loss: government spending on public goods introduces different inefficiencies, perfect competition maximizes welfare (not creates a loss), and shifting producer surplus without changing consumer surplus describes a redistribution rather than a deadweight loss.