A detailed analysis of Portugal's loss of managerial resources is contained in Harry M. Makler's follow-up surveys of 306 enterprises, conducted in July 1976, and again in June 1977. His study makes clear that nationalization was greater in the modern, large, and technically advanced industries than in the traditional ones such as textiles, apparel, and construction. In small enterprises (50–99 employees), only 15 percent of the industrialists left as compared with 43 percent in the larger organizations. In the largest firms (1,000 or more employees), more than half left. Makler's calculations show that the higher the socioeconomic class of the person, the greater the likelihood that they had left the firm. He also notes that "the more upwardly mobile also were more likely to have quit than those who were downwardly socially mobile." Significantly, a much larger percentage of professional managers (52 percent) compared with owners of production such as founders (18%), heirs (21%), and owner-managers (32%) had left their enterprises.