ON INSTANTANEOUS AND FINITE BIRTH RATES1

Abstract

A formula relating instantaneous and finite birth rates, originally derived by Leslie, is presented and compared with the formula of Edmondson. It is shown that Edmondson’s formula is a special case of Leslie’s, valid when there is no mortality. The bias involved in the use of Edmondson’s formula in cases where mortality is nonzero is examined. Since Leslie’s formula requires no new assumptions or data, it should be used in place of Edmondson’s formula.