Did almost 300k children get married in 2000–2018 in the USA?

Question

The article Child Marriage in the United States: Prevalence and Implications from the Journal of Adolescent Health makes the following shocking claim right at the top:

We found that some 297,033 children were married in the U.S. between 2000 and 2018: 232,474 based on marriage-certificate data plus 64,559 based on estimates (Table 1). A few children were as young as 10 years when they married, but of those for whom age information was available, nearly all—96%—were aged 16 or 17 years.

In a country with a population of 300 million and change, this suggests that over an 18-year period, approximately 1 person in 1000 of the entire population became an underage bride or groom. (At a time when overall marriage rates are at an all-time low and declining, no less!) And if 96% of these (about 223,000) were 16- or 17-year-olds, there are a lot fewer of them than there are of the entire population.

A bit of back-of-the-napkin math with census data suggests there were probably somewhere between 2-3 million 16- and 17-year-olds in the USA in 2018. Divide that 223,000 by 18 and you have about 12,400 cases each year, or in other words, somewhere around 0.5% of all 16- and 17-year-olds in the country getting married every single year. (Yes, this is very oversimplified math, but the figures should be in the right ballpark.)

That seems a bit excessive to say the least. Is there any reason to believe these figures are anywhere near accurate? If not, how did the researchers manage to come up with such wildly wrong figures?

Answer 1

Firstly, let's take the emotive language out of the claim. The report takes the definition of "child marriage" to be a marriage involving any party under the age of 18 years old, and clarifies that:

of those for whom age information was available, nearly all—96%—were aged 16 or 17 years

The headline figure also covers marriages conducted over a span of 19 years, and includes some uncertainty, between 200 thousand and 300 thousand married children.

On average, that's between 10 thousand and 16 thousand 16- and 17-year-olds marrying in the US each year. One of the tables in the report shows how that's declined over the period studied, from a lower-bound estimate of 76,396 in 2000 to only 2,493 in 2018.

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The US Census Bureau published a report in 2021 titled "Number, Timing, and Duration of Marriages and Divorces: 2016". It is based on the 2016 American Community Survey (ACS) 1-year estimates, a weighted sample survey of about 3.5 million households.

Table 2 breaks down marital status by age groups, with the youngest group being "15-17 years". This age group is listed with a total population of 6,480,000 men plus 6,170,000 women, of whom 0.8% are classed as "ever married". Appendix C lists the corresponding margins of error as 14,690 plus 11,400 population and 0.1% "ever married".

That comes out at 88,367 to 114,084 people in the US population who were married before age 18.

There's a few reasons why that number isn't directly comparable with the Unchained at Last estimate:

1. We don't know what year these people got married in. From the bare statistics, it's possible the marriages in question were spread over 17 years, giving as few as 3 thousand per year; but that would require as many 1-year-olds marrying as 17-year-olds. What we can say is that if the Unchained at Last numbers are true, and it's true that those numbers are mostly 16- and 17-year-olds, then the relevant years are 2015 and 2016, where they estimate at least 4,275 and 3,695 child spouses, respectively. So the comparable Unchained at Last number would be around 8 thousand who were "ever married" in 2016.
2. The survey would include anyone who married abroad, then moved or returned to the USA, as long as all of that happened before the age of 18.
3. The survey respondents may be including marriages which weren't conducted legally at all, but were recognised as such by their local community.

These factors may account for the ACS figure being significantly higher, but it suggests that the Unchained at Last figures are not wildly improbable. Unlike Unchained at Last, who are a campaign group, the Census Bureau has no motivation to exaggerate this particular figure.

Answer 2

A bit of back-of-the-napkin math with census data suggests there were probably somewhere between 2-3 million 16- and 17-year-olds

Really there are over 8.5 million who are/were 16 or 17

That seems a bit excessive to say the least. Is there any reason to believe these figures are anywhere near accurate? If not, how did the researchers manage to come up with such wildly wrong figures?

They aren't that wildly wrong, but the statement that there were 76,396 children married in the year 2000 seems suspect. The US Public Broadcasting Service says 23,582 were married in the year 2000.