The More Responsive Quantity Supplied Is to a Change in Price, the More Elastic the Supply Curve Beginning at point a, an increase in price from $40 to $50 causes a small increase in quantity supplied along supply curve I, from 80 to 85 units (at point c). But the same increase in price causes a big increase in quantity supplied along supply curve E, from 80 to 170 units (at point b). Since the quantity supplied is more responsive to a change in price, supply curve E is more elastic than supply curve I.