Competitive Closings Of Least Productive Firms Raises US Productivity Average

My published comment to The Wall Street Journal article, "Rising Education Levels Provide Diminishing Economic Boost: Share of workers with college degrees has kept growing, but productivity gains have been tepid" by Josh Mitchell:

US productivity statistics are an average of the economy. Competitive closings of the least productive firms raises the US productivity average. The firms that remain in business do not need to become more productive for US productivity to rise. As long as the least productive firms that are closing on average have lower productivity than the average of the firms that remain, whether or not the remaining firms increase productivity, the economy wide productivity numbers will show an increase. The change in US productivity represents additive factors: the effect of low productivity firms closing, the effect of remaining firms that do not increase productivity but have a higher productivity than the closing firms, and the effect of firms that can increase the productivity of their output. When there are fewer low productivity firms in the economy and more higher productivity firms surviving, average US productivity will not show historical large productivity increases.