Borders J A, Cutright P
Fam Plann Perspect. 1979 Jul-Aug;11(4):227-33.
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.
堕胎服务的可及性——提供堕胎服务的机构数量和类型——是美国大都市社区堕胎率差异的最有力决定因素。堕胎服务可及性的增加也是解释1973年至1975年期间堕胎率上升的最重要因素。影响堕胎率的其他因素（但影响较小）包括农村居住情况、人口密度、女性劳动力参与率、天主教徒比例以及接受公共援助的比例。
