Table of Contents

Effects of Abortion on the U.S. Population

In 1973, the Supreme Court addressed the issue of abortion in two cases, Roe v. Wade and Doe v. Bolton. The Court’s holding in Roe and Doe had the effect of legalizing abortion on demand through all nine months of pregnancy.1) Prior to the federal legalization of abortion, states had the authority to independently determine abortion’s legality. Although states could still impose restrictions in the second and third trimesters of pregnancy, 1973 marked the year in which all states were required to legalize abortion.

Roughly 53 million abortions were reported between 1973 and 2011.2) The Guttmacher Institute estimates that there were 1.1 million abortions in 2011 (the lowest yearly rate of abortions in the U.S. since 1973).3)

Legalizing abortion massively changes sexual behaviors outside of marriage. The consequent sexual revolution increases conception out-of-wedlock and increases the rate of venereal diseases. In a country of a few million births per a year, these increases themselves approach the millions. The additional disease transmission vector comes with a cost around $300 million annually, paid collectively by individuals and through taxes.4)

U.S. Abortion Rate, 1973-2011

1. Legalizing Abortion Changes Sexual Behavior

Abortion affects sexual activity. Whereas previously the expected consequence of sexual activity–conception and birth–previously discouraged sexual behavior (particularly outside of marriage), the legalization of abortion removed the consequence of childrearing and therefore increased sexual activity.5) The availability of a new option to abort one’s child has resulted in a greater number of children being conceived than there would have been had sexual behavior retained the normal result of a child being born.

According to the Center for Disease Control, 15 percent of children aborted were children of married mothers6) while the remaining 85 percent of children aborted are the children of unmarried mothers. Eighty-five percent of abortions are by unmarried mothers. These unwed mothers changed their sexual behavior.

At most, all 15 percent of abortions by married mothers are conceptions that would not have occurred had abortion not been legalized. Similarly, the abortion rate before legalization was roughly 10 percent of what it became after legalization.7) Sixty-six percent of abortions are conceptions that would not have occurred but for changed sexual behavior.8) This means at least 40 percent9) of abortions are conceptions by unmarried women that occur as a result of sexual activity that would not have occurred without abortion legalization.

Legalizing abortion increases sexual behavior outside of wedlock. Around 600,000 children—40 percent of 1.5 million abortions, and around 15 percent of the total number of births (4 million)—are now destroyed annually on account of being conceived out of wedlock because abortion was legalized. This is a massive social and ecological effect abortion has on sexual behavior. Legalizing abortion creates a massive amount of new out-of-wedlock conceptions that will then be destroyed.

2. Effects of Abortion on the Birthrate

The effect of abortion on birthrate is not simply the raw number of reported abortions; rather, abortions reflect both births that would have otherwise taken place, and children that were only conceived because of how abortion changes society. The total number of abortions minus the number of children that would not have been conceived absent the legalization of abortion better indicates the effect of legalized abortion on the birthrate.

Since abortion has resulted in increased sexual intercourse, and hence in increased conception, researchers must isolate the number of pregnancies that would not have occurred if abortion had not been legalized. It is first necessary to determine the impact of abortion on total births. Then, by determining this impact of abortion, the percentage of aborted children that otherwise would not have been conceived can be determined.

Prior to the ruling in Roe v. Wade, states individually determined the legality of abortion. This phenomenon of these states individually legalizing abortion (at different times) creates a natural experiment. This experiment shows that the greater the distance from the closest early legalizing abortion state, the less likely a woman is to abort her child. This natural experiment then shows that legalizing states experience a 10 percent decline in birthrate compared to non-legalizing states far away. Early legalizing states demonstrate the direct effect of abortion on birthrate. Non-legalizing states far away serve as a kind of control group for abortion’s impact on birthrate.10)

From the 1970s through the 2000s the number of live births averaged approximately four million per year. While over this period the U.S. population has increased, the fertility rate (birthrate) in the U.S. has decreased per (fertile) adult. An increase in the U.S. population has compensated for the per adult decrease in fertility. The “natural experiment” among the states shows that abortion causally reduces births by around 10 percent.11) Had abortion not been legalized, approximately a third of aborted children would be present today.12)

3. Economic Impact of Abortion

Eliminating a population through abortion destroys a population that will work and pay taxes. Legalizing abortion imposes a loss of between $70 billion and $135 billion of economic activity (valued work),13) and between $10 billion and $33 billion in annual tax revenue.

1) Roe v. Wade and Doe v. Bolton legalized abortion up until the moment of birth if a physician willing to perform the abortion deems it necessary for the mother’s health. The Court cites a broad range of examples that fall under “health,” such as the “stigma of unwed motherhood,” the work of “child care,” and “the distress, for all concerned, associated with the unwanted child.” Dr. Warren Hern, author of Abortion Practice and contributor to the National Abortion Federation Program Standards for Abortion Services (first version), stated, “I will certify that any pregnancy is a threat to a woman's life and could cause grievous injury to her physical health.”
See Roe v. Wade, 410 U.S. 113 (1973) and 410 U.S. 179 (1973).
2) Rachel K. Jones and Jenna Jerman, “Abortion Incidence and Service Availability in the United States, 2011,” Perspectives on Sexual and Reproductive Health 46, no. 1 (2014): 3-14 as cited in “Induced Abortion in the United States,” The Guttmacher Institute, July 2014, available at http://www.guttmacher.org/pubs/fb_induced_abortion.html.
3) “Induced Abortion in the United States,” The Guttmacher Institute, July 2014, available at http://www.guttmacher.org/pubs/fb_induced_abortion.html.
4) Jonathan Klick and Thomas Stratmann, “The Effect of Abortion Legalization on Sexual Behavior: Evidence from Sexually Transmitted Diseases,” Journal of Legal Studies 32 (2003): 407-433. If legalizing abortion can be presumed to have a similar (causal) effect on the transmission of other sexually transmitted diseases, legalizing abortion creates treatment needs costing something around $4 billion annually.
5) Elizabeth Oltmans Ananat, Jonathan Gruber, Phillip B. Levine, and Douglas Staiger, “Abortion and Selection,” The Review of Economics and Statistics 91, no. 1 (2009): 124-136, p. 127 (first two full paragraphs, and succeeding analysis) gives an independent, parallel elucidation of this fact. The model developed also shows that the effect on sexual behavior dealt with throughout this entry endures over the decades following the legalization of abortion. An independent demonstration of the relative consistency (and reversibility) of the sociological phenomenon investigated here (abortion legalization affecting human fertility) is found in the analyses of the Eastern European countries performed in Philip Levine, Sex and Consequences: Abortion, Public Policy, and the Economics of Fertility (Princeton University Press, 2007).
Note, too, these correspond with assertions on abortion popularized in Steven Levitt and Stephen Dubner, Freakonomics: A Rogue Economist Explores the Hidden Side of Everything (William Morrow, 2005).
6) U.S. Department of Health and Human Services, Center for Disease Control and Prevention, Abortion Surveillance—United States, 2009, by Kim D. Burley et al. Surveillance Summaries, 61, no. 8. Table 17, “Reported abortions, by known marital status and reporting area of occurrence—selected states, United States, 2009” Available at http://www.cdc.gov/mmwr/pdf/ss/ss6108.pdf (accessed June 25, 2013).
7) The number of illegal abortions may be estimated by a method pioneered in Philip Levine, Sex and Consequences: Abortion, Public Policy, and the Economics of Fertility (Princeton University Press, 2007) and used in Elizabeth Oltmans Ananat, Jonathan Gruber, Phillip B. Levine, and Douglas Staiger, “Abortion and Selection,” The Review of Economics and Statistics 91, no. 1 (2009): 124-136. The calculation is available upon request. It compares retrospective questions in NSFG Cycle 3 (a 1982 survey containing questions concerning 1965 through 1968) and NSFG Cycle 5 (a 1995 survey containing questions concerning 1978 through 1981).
8) See Henry Potrykus and Anna Higgins, “Abortion: Decrease of the U.S. Population & Effects on Society,” The Marriage and Religion Research Institute (January 2014), available at http://marri.us/research/research-papers/abortion-us-population/.
9) 66 percent – 15 percent – 10 percent ≈ 40 percent
10) This is done in Philip Levine, Sex and Consequences: Abortion, Public Policy, and the Economics of Fertility (Princeton University Press, 2007).
11) Philip Levine, Sex and Consequences: Abortion, Public Policy, and the Economics of Fertility (Princeton University Press, 2007). Figure 5.6 clearly and explicitly illustrates this impact of abortion legalization on birthrate. Albeit likely, this number is somewhat higher than another figure used in the literature (somewhat above 6 percent). See Abortion: Decrease of US Population and Effect on Society for an analysis as to how using the lower figure (6 percent) modifies the findings that follow. In fact, all the findings are robust to the uncertainty in this effect on birthrate: The numbers stated in this entry are conservative.
12) (4 million births per year) x (10% decreased birthrate) = 400,000 births (that would have been) lost to abortion. So, 400,000 / 1.2 million annual abortions = 33 percent of aborted children would be present today.
13) Assuming an average income of $14,000 to $27,000 per aborted worker per year times 5 million lost persons who would be working now gives $70 billion to $135 billion per year lost in valued economic activity (work). The median U.S. income per worker is around $40,000 per year. $40,000 is 150 percent of $27,000. See Abortion: Decrease of US Population and Effect on Society for how this (much) lower value (median worker having income 50 percent higher than aborted worker) for the average aborted worker is obtained.


This entry draws heavily from Abortion: Decrease of U.S. Population and Effects on Society.