Does that data include contractors? As we know well, companies often use contractors as large parts of their labor forces and to fill important roles. In the a

Does that data include contractors? As we know well, companies often use contractors as large parts of their labor forces and to fill important roles. In the article's data, the differences between the companies could depend to a great degree on the variation in employment relationships (i.e., contractor or employee) and not in the productivity of labor.