The four-firm concentration ratios for industries X and Y are 80 percent and 61 percent, respectively, while the corresponding Herfindahl-Hirschman indexes are 3,700 and 2,100. The Dansby-Willig performance index for industry X is 0.68, while that for industry Y is 0.75.

Based on this information, which would lead to the greatest increase in social welfare: a slight increase in industry X's output, or a slight increase in industry Y's output?

• A slight increase in industry Y's output.
• A slight increase in industry X's output.