The reproduction rates computed in the past have been age-adjusted, i.e. based on age specific birth rates. Because order of birth and parity of mother were ignored, these rates have had an upward bias in some years and a downward bias in others. The omission of an allowance for marriage and fecundity has had a similar effect. The reasons for these biases are analyzed; a method for utilizing age-parity specific rates and allowing for spinsterhood and sterility is described; and the different types of rates are shown for selected years.