This supplementary analysis (not shown in tables) confirmed that the results in table 2 are robust. We note that size, in terms of the number of employees, clearly predicts the existence of formal strategies. Firms having a formal HRM strategy are on average about twice as large as those without such a strategy. Corporate subsidiaries tend to have both policies and practices in place to a greater extent than independent firms. The presence of an HRM department within the organization also positively affects the use of elaborate practices. These findings support hypotheses 1 through 3 and consequently our assumption that resource constraints are important determinants of investments in more advanced HRM.