Community determinants of U.S. legal abortion rates.

The availability of abortion services--the number of facilities and the number of types of agencies providing abortions--is the most powerful determinant of variations in abortion rates in U.S. metropolitan communities. The increase in abortion availability is also the most important factor in explaining the increase in abortion rates that occurred between 1973 and 1975. Other factors affecting abortion rates (but less substantially) include rural residence, population density, female labor force participation, the proportion Catholic and the proportion receiving public assistance.