Which term refers to the unused world oil production capacity?

• A. Operating capacity
• B. Spare Capacity
• C. Reserve capacity
• D. Idle capacity

Answer: (B)

Spare capacity is the production capacity that isn’t being used right now but can be brought online quickly to meet higher demand or cover a disruption. It acts as a buffer in oil markets, allowing producers to stabilize supply and influence prices by ramping up output on short notice. This is why it’s the best term: it explicitly conveys an unused, ready-to-use capacity above current production. Operating capacity is what’s currently producing, so it isn’t about unused, ready-to-respond capacity. Idle capacity is unused but doesn’t inherently imply a planned, quick-restart buffer, and reserve capacity isn’t the standard label for this concept in oil-market discussions. Spare capacity is the conventional phrase for this ready-to-activate excess.