The Marriage Advantage for Fertility

As the evidence shows, marriage is a child-centered institution. Of course, having children doesn’t legitimize any one couple’s marriage over another’s, but a healthy marriage does benefit kids, and marriage means the ability to have the children women say they want. Canadian survey data show one reason women who want children aren’t having them is the lack of suitable partners.¹

Canada recorded a historic low total fertility rate (TFR) of 1.33 births per woman in 2022. A population requires a TFR of 2.1 to replace itself from generation to generation.² The TFR in the United States was only slightly better in 2022, at 1.66. Fertility across North America is now so low that politicians, policymakers, and public commentators are compelled to address the issue.

Many economic and cultural factors have contributed to declining fertility in Western countries and across the globe, and the decline of marriage is one contributing issue. Most births in Canada and the United States are to married women, but adults in both countries are marrying less and at later ages, compared with several decades ago. The increase in the age at first birth results in a shorter period to have the number of children couples desire. In many countries there is a gap between the actual fertility rate and desired fertility. While many believe low fertility represents increased female empowerment, there is substantial evidence in North America that our low fertility rates represent, in part, unfulfilled life goals.

Furthermore, US data show that the overwhelming majority of abortions occur among unmarried women. “The vast majority of women who had abortions in 2021 were unmarried (87 percent), while married women accounted for 13 percent, according to the CDC, which had data on this from 37 states,” Pew Research tell us.³ While data on abortion by marital status is not readily available in Canada, over half of all abortions happen among women younger than the average age of first marriage. Without diving into the thorny issue of abortion, it’s still worth noting that over eight in 10 abortions in the United States happen among women who are not married. If we accept that abortion is a difficult thing for any woman to undergo, we can then imagine that married couples are more likely to have the economic means and social and family support to navigate unplanned pregnancy, compared with the level of support among many unmarried women facing similar circumstances. Surveys show that women want to have more children than they are currently having, but under the right circumstances—marriage being a key factor.

Multiple factors contribute to the global decline in fertility rates; however, marriage and fertility remain firmly linked.⁴ Absent a marriage-friendly culture, fertility rates will not increase, and women will not have the number of children they desire.

Editor's Note: This essay is an excerpt from I...Do? Why Marriage Still Matters (Cascade Books, 2024) by Andrea Mrozek and Peter Jon Mitchell. It has been reprinted here with permission.

1. Lyman Stone, “She’s (Not) Having a Baby. Why Half of Canadian Women Are Falling Short of Their Fertility Desires” (Hamilton, ON: Cardus, January 2023).

2.The TFR is an estimate of the number of children that a hypothetical woman will have over her lifetime, based on age-specific fertility rates within a given year. Canada has not recorded a replacement level TFR of 2.1 since 1971.

3. Diamant, Jeff, et al. “What the Data Says about Abortion in the US.” Pew Research Center, May 27, 2022. Updated Mar. 25, 2024. 

4. Lyman Stone and Spencer James, “Marriage Still Matters. Demonstrating the Link between Marriage and Fertility in the 21st Century” (Institute for Family Studies, & Wheatly Institute, October 2023), https://ifstudies.org/ifs-admin/resources/reports/marriagestillmatters-final.pdf.