Resolution criteria
This market will resolve to the first year in which the global total fertility rate falls below the replacement level of 2.1 children per woman. The TFR is defined as the average number of children a woman would have over her lifetime based on current age-specific fertility rates.
The resolution will be based on data from the United Nations Population Division, unless someone makes a compelling argue for using another source.
Background
The global TFR has been on a steady decline over the past several decades. In 1950, the global TFR was approximately 4.84 children per woman, which decreased to 2.23 by 2021. This decline is attributed to factors such as increased access to education and employment for women, improved child survival rates, and greater availability of contraception. Projections indicate that the global TFR will continue to decrease, potentially falling below the replacement level of 2.1 in the near future. (healthdata.org)
Considerations
While the global TFR is approaching the replacement level, regional variations are significant. Many high-income countries have already experienced TFRs below 2.1 for several years, whereas some low-income countries, particularly in sub-Saharan Africa, maintain higher fertility rates. These regional differences may influence the timing of when the global TFR falls below the replacement level. Additionally, data collection and reporting methods can vary between sources, potentially affecting the exact year identified for this demographic milestone.
How do extrauterine births change the calculus, is it still per live women's lifetimes even though it won't be the women giving the birth. I could imagine a reversal of the trend, once labor itself is taken out of the equation at least for part of the gestation. Though perhaps a counter argument would be that it is the child rearing itself and not labor in the womb that is the turn off, along with moral sentiments