Abstract: Problem statement: incidence of abortion in the United States has steadily declined since 1990. The question is why? Approach: This study, using multiple linear regression, examines whether women's unprotected sexual activity is deterred by the risk of contracting AIDS as reflected in decreased abortion rates. Results: The empirical evidence consistently finds that the prevalence of AIDS reduces the risky (unprotected) sexual activity of women of childbearing ages 15-44 as reflected in their abortion rates. The empirical results remain robust for the abortion rates of teens ages 15-17 and for teens ages 15-19. Conclusion: The empirical results suggest that the behavioral modification induced by the prevalence of AIDS accounted for 21% of the decrease in abortion rates over the time period 1992-2005.
Key words: AIDS, abortion, sexual behavior
The incidence of abortion in the United States has declined steadily since peaking in 1990. The 1.21 million abortions performed in 2005 represent a 25% decline from 1990. The U.S. had fewer abortions in 2005 than it had in 1976, even though there were 4.5 million more females of childbearing age. Similarly, the abortion rate decreased from 27.4 abortions per 1000 women ages 15-44 in 1990-19.4 in 2005. The abortion ratio fell from 28.0 abortions per 100 pregnancies in 1990-22.4 in 2005 (Jones et al., 2008).
A variety of plausible reasons have been offered to explain this dramatic decline: (1) welfare reform; (2) a decline in the numbers of abortion providers; (3) enactment of informed consent laws that mandate physicians/clinics provide to women seeking an abortion, medical information (e.g., fetal pain, breast cancer, financial assistance) designed to dissuade a woman from having an abortion; (4) use of more efficacious methods of contraception (e.g., Norplant and Depo-Provera); and (5) changing demographic factors (Sawhill, 2006).
However, none of these factors provide an entirely satisfactory explanation for the steady decline in abortion since 1990. First, substantive welfare reform did not occur until 1996 with the passage of the Personal Responsibility and Work Opportunity Reconciliation Act. Second, in 2005, there were 1787 abortion providers; a decline of 25% from 1992. But, most of the decline was providers with small abortion caseloads. In 2005, there were 401 providers with large caseloads (1000+ abortions) that provided 80% of all abortions (Jones et al., 2008). Third, informed consent laws place no restrictions on abortion access or availability. Fourth, highly reliable and injectable contraceptive methods were used by less than 4% of all contraceptive users in 1995 (Piccinion and Mosher, 1998). Fifth, the proportion of women of childbearing age between the most sexually active ages of 18-24 years increased from 1990-003 (Finer, 2007).
While acknowledging that the above factors may have contributed to the fall in the incidence of abortion, another important factor that may be responsible for the decline in abortion is the emergence and spread of the Acquired Immune Deficiency Syndrome (AIDS) virus. The AIDS virus was first identified in late 1981. By 2005, more than 925,000 cases of AIDS had been reported in the United States, while over 550,000 individuals had died from AIDS (Centers for Disease Control, 2005).
In a seminal article, Kane and Staiger (1996) argue that women's decisions regarding their level of risky (unprotected) sexual activity are endogenous. Increases in the cost of engaging in risky sexual activity may alter women's initial decisions concerning the frequency of unprotected sexual activity, thereby reducing the likelihood of an unintended pregnancy and, consequently, an abortion. Given the fatal consequences of AIDS, sexually active women may be induced to use condoms or abstain from sexual activity, as the risk of contracting AIDS increases. Thus, another reason why the incidence of abortion has declined since 1990 is that the rise in the prevalence of contracting AIDS may have decreased the level or frequency of women's unprotected sexual activity causing a reduction in the number of unintended pregnancies and, concomitantly, a decline in abortions. …