Interactive oil shortage: a supply cut, a price ceiling, and the gap the ceiling opens supply falls Shortage S S1 D Ceiling P2 P3 P1 Qs = Q2 Qd = Q3 Q1 Value burned waiting in line Quantity of oil Price ($) Supply fell to S₁ (3.5 units). Ceiling at 5.0 → buyers want 5.3. Qd 5.3 vs Qs 3.5 → a shortage of 1.8 units. The cap can’t undo the supply cut — it opens a 1.8-unit shortage, and waiting in line burns the gap between the capped price and what the scarce gasoline is worth. Drag the dashed ceiling up or down, or tab to it and use the arrow keys. It snaps at P₁, the old price, and P₂, the new one.