The four-firm concentration ratios for industries X and Y are 68 percent and 79 percent, respectively, while the corresponding Herfindahl-Hirschman indexes are 1,800 and 2,900. The Dansby-Willig performance index for industry X is 0.65, while that for industry Y is 0.78. 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?