From Reuters today, in the article Supreme Court conservatives appear willing to gut abortion rights:
About one in four American women has had an abortion, [attorney Julie] Rikelman added.
According to the article, this statement was made during oral arguments. Per the Associated Press, the case being argued is Dobbs v. Jackson Women’s Health Organization.
Is the quoted statement true?
TL/DR: Rikelson's actual claim is supported by a 2017 estimate. The quoted claim is slightly different.
Population Group Abortion Rates and Lifetime Incidence of Abortion: United States, 2008–2014 was published in 2017, but was based on 2008-2014 data (so these figures are around a decade old).
They used survey data from around 8,380 women who had had abortions, and other sources to make an estimate of the lifetime incidence of abortion.
an estimated 23.7% of women aged 15 to 44 years in 2014 will have an abortion by age 45 years if the 2014 abortion rates continue throughout their reproductive lives.
This is a drop from earlier estimates:
The proportion of women expected to have an abortion by age 45 years declined from 30% in 2008 to 24% in 2014. This pattern parallels, but was less pronounced than, the decline in the abortion rate during that same period. That nearly 1 in 4 women is anticipated to have an abortion during her reproductive years demonstrates that it is not an uncommon experience.
The paper describes several potential sources of error and bias in the production of this estimate, but it seems a reasonable basis from which to make the claim.
@fredsbend makes a legitimate point that there is a nuanced distinction between the claim in the question that 1 in 4 women have had an abortion, versus this reference that estimates (slightly under) 1 in 4 women will have had an abortion.
I investigated what was actually said in the Supreme Court case being discussed:
On page 48 of the transcript (p49 of the pdf), attorney Julie Rikelson says:
one out of every four women makes the decision to end a pregnancy.
I read that as matching the study, and shows that the Reuters article slightly misquotes her.
Meanwhile, on page 96 of the transcript (p97 of the PDF), the Solicitor General Elizabeth Prelogar claims:
one in four American women have had an abortion
which is subtly different and would be an overestimate, compared to the study result.
This is likely skewed and inaccurate.
It makes assumptions based on questionnaires response average rate and extrapolates it to the whole population.
Here are just three reasons why this is wrong:
Just because there are a number of abortions compared to a population of women doesn't adequately explain the percentage of women who've had abortions. There are some women who choose not to have any abortions and some women who have many- this skews the mean, sometimes called an average. (Mean vs Median- https://data36.com/statistical-averages-mean-median-mode/)
Abortion is a highly, politically-charged topic which causes many to misreport, both in favor and against. Using questionnaires to acquire data is one of the least accurate ways to obtain data generally, and especially in controversial or politically-charged topics. Taking samples of women in a city that have had an abortion or those who have not based on medical records would be far more accurate. (Direct measurement is more accurate than questionnaires - https://ijbnpa.biomedcentral.com/articles/10.1186/1479-5868-5-56)
Because this is a highly, politically-charged topic, advocates will likely overstate the strength of the data. It would require peer review by an opposing body or at least a neutral one to adequately validate the data. (Politics is like the "dark side," it clouds everything- https://phys.org/news/2020-10-election-polls-confident-accurate.html)
