The four-firm concentration ratios for industries X and Y are 79 percent and 62 percent, respectively, while the corresponding Herfindahl-Hirschman indexes are 3,100 and 2,000. The Dansby-Willig performance index for industry X is 0.70, while that for industry Y is 0.81.

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?

multiple choice

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