Between 2002 and 2022, total MLB strikeouts per season rose while the US fertility rate fell, correlating inversely at -0.9648 across twenty data points. The implication that baseball's increasing reliance on power pitching is somehow reducing American birth rates is the kind of theory that sounds absurd until you consider the length of a modern baseball game. Nine innings of three-true-outcome baseball takes long enough to functionally prevent any other evening activity, including the one that produces children. The data cannot confirm this hypothesis, but the average game time of 3 hours and 6 minutes does not refute it.
MLB strikeouts per season grew from roughly 30,000 in 2002 to over 42,000 by the early 2020s, driven by increased pitch velocity, the three-true-outcomes approach, and bullpen specialization. The US fertility rate declined from approximately 2.0 births per woman in 2002 to 1.64 by 2022, driven by rising childcare costs, student debt, delayed marriage, and shifting cultural priorities. Both are secular 20-year trends driven by entirely separate institutional and demographic forces.
Twenty data points of one metric rising and another falling will almost always produce a strong inverse correlation. Baseball strategy and reproductive decisions share a two-decade timeline, not a mechanism.
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Want to learn more about why correlations like “US fertility rate” vs “Total MLB strikeouts per season” don't prove causation? Read our guide to statistical thinking.
