... mightinvest in inventories, but to the extent to which the suppliers of those inventoriesgrant credit, the net investment in inventories is reduced. Firms pay wages, but to theextent to which ... are introduced to explain both operating andfinancing profitability and overall shareholder profitability. 1.1. Distinguishing the Profitability of Operations from the Profitability of FinancingActivitiesWith ... rate.The top federal statutory corporate tax rate was 52% in 1963, 50% in 1964, 48% in 1965–1967, 52.8% in 1968–1969, 49.2% in 1970, 48% in 1971–1978, 46% in 1979–1986, 40% in 1987, 34% in 1988–1992...