Even in countries with high rates of legal induced abortion, contraceptive use and marital patterns nearly always have a greater impact on fertility levels than does abortion. As a rule, extremely high rates of abortion--three or more abortions per woman of childbearing age during the reproductive years--are required for the fertility-inhibiting effect of abortion to rival that of contraceptive use. Nevertheless, the absolute effect of abortion on fertility (defined as the amount by which the current total fertility rate, or TFR, would increase if no abortions were performed) is often substantial. In most of the countries examined, the TFR would have been from about 20 percent to nearly 90 percent higher than it actually was (other things being equal) had no induced abortions been performed. Among developed countries, the Soviet Union, Japan, Eastern European countries, Israel and the United States have the highest total legal abortion rates, ranging from one abortion to more than five abortions per woman of childbearing age during the reproductive years. Among the developing countries for which reliable data are available, South Korea, China, Cuba and Singapore have rates of about 1-2 abortions per woman of fertile age. However, a number of other countries in Latin America and Asia, for which the data are deficient, probably have equally high rates.