Excess Births during the COVID-19 Pandemic
Excess Births during the COVID-19 Pandemic
The COVID-19 pandemic led to a decline in births in 2020 followed by a rebound in 2021. We present new estimates of “excess” births during the pandemic, which show that on net over the two-year period, births were roughly in line with pre-pandemic trends.
Key Points
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From January 2020 to February 2021, 70,000 fewer births occurred than expected based on pre-pandemic patterns.
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Over the course of 2021, birth rates rebounded to levels above pre-pandemic norms. By December 2021, the cumulative number of births had nearly returned to its expected value if the pandemic had not happened.
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In 2021, the number of births by college educated women aged 25-39 rose greatly above its expected value. The relative increase in fertility was greatest among college educated women aged 25-29. In 2021, about 40,000 excess births were attributable to college educated women aged 25-49.
The COVID-19 pandemic led initially to a decline in the number of births in 2020 followed by a rebound in 2021. Previous research has found that births in the U.S. fell below pre-pandemic trends in 2020 but exceeded them in 2021, and identified similar patterns in other high-income countries.
In this brief, we present new estimates of the pandemic’s impact on U.S. fertility. While much of the prior research has relied on extrapolating aggregate pre-pandemic linear trends to infer what would have happened if there had been no pandemic, we instead adapt methods used to measure excess mortality related to COVID-19.
To estimate “excess” births during the pandemic, we first estimate monthly expected births given recent fertility patterns. We deem an observed count of monthly births to be in “excess” if the number of observed births is statistically different (in either direction) from expected births under pre-pandemic trends. Otherwise, we use the observed value as the expected number of births. We then define the difference between observed and expected births to be the number excess births. This method provides estimates more robust to the random nature of the natality process than simply defining excess to be the difference between observed births and a pre-pandemic trend, regardless of how unexpected the observed value is.
Figure 1 plots estimated expected births in 2020 in 2021 against the actual observed number of births. Note that births exhibit strong seasonality, peaking in the summer and falling in winter, which is reflected in expected births. Births began to drop consistently below expectations in August of 2020 and then plummeted in late 2020 to early 2021, bottoming out with 21,000 fewer births than expected in February 2021. However, from April 2021 onwards, the number of births leapt back up and maintained or outpaced expectations for most of the year.
Source: Penn Wharton Budget Model estimates from National Vital Statistics System and Census Bureau data.
Figure 2 shows cumulative monthly excess births during this period. In total, negative excess births in 2020 and early 2021 reduced the number of births by 70,000 through February 2021, relative to expectations. The boom of positive excess births in 2021 reversed this decline, however, and by the end of 2021 had largely offset the previous year’s shortfall.
Source: Penn Wharton Budget Model estimates from National Vital Statistics System and Census Bureau data.
Annually, Table 1 shows that there were around 36,000 fewer births in 2020 and 34,000 more births in 2021 than expected, for a net effect close to zero over the two-year period.
| 2020 | 2021 | Net | |
|---|---|---|---|
| Total Births | 3,617,034 | 3,666,993 | 7,284,027 |
| Excess Births | -36,287 | 33,947 | -2,340 |
The massive decline in expected births during the later months of 2020 and the early months of 2021 was anticipated as a behavioral fertility to public health and economic conditions during the first few months of the pandemic. Moreover, many of the ‘missing’ births from earlier in 2020 have been attributed to a decline in immigration of pregnant women due to travel restrictions and behavioral response. However, the rise in fertility to levels exceeding pre-pandemic trends was unanticipated. To analyze this pattern further, we examine excess fertility across age and educational attainment.
To compare the excess fertility across socio-demographic groups, we calculate the percentage relative excess births (sometimes called the “P-score”), defined as the ratio of excess births to expected births multiplied by one hundred. We refer to this measure as the “relative excess.” Groups with positive (negative) relative excess experienced a rise (drop) in fertility relative to pre-pandemic trends.
Source: Penn Wharton Budget Model estimates from National Vital Statistics System and Census Bureau data.
Fertility fell below expectations in 2020 for all age groups except ages 15-19, which saw a slight relative increase in 2020, as seen in Figure 3. In 2021, fertility rose above pre-pandemic trends among ages 15-29 and 35-39, with women aged 25-29 experiencing the largest relative increase in births. Fertility among early women in their early 30s was slightly below expectation, whereas fertility in women 40-49 remained depressed, despite some recovery from declines in 2020.
Source: Penn Wharton Budget Model estimates from National Vital Statistics System and Census Bureau data.
In 2021, fertility exceeded expectations among college-educated women aged 25-39. Notably, relative excess fertility rose to nearly 10% among college-educated women aged 25-29 (see Figure 4). Women older than 39 and younger women without college degrees generally maintained levels of fertility slightly below expectation in 2020 and 2021.The greatest magnitude change in relative fertility was among women aged 45-49, an effect attributable to low expected fertility rates.
In general, we find excess fertility in 2021 was driven by two groups: women aged 15-24 and college-educated women aged 25-39. In particular, the boom in births by college-educated women aged 25 to 29 resulted in around 26,000 excess births, accounting for nearly 80% of all excess births in 2021. A suggested explanation for this pattern is that during the pandemic women who otherwise would have delayed having families chose to begin them.
This analysis was produced by Duncan Haystead under the direction of Alex Arnon and the faculty director, Kent Smetters. Mariko Paulson prepared the brief for the website.