Slightly more births at full moon
Comptes Rendus. Mathématique, Volume 359 (2021) no. 7, pp. 805-811.

A popular belief holds that the number of births highly increases when the moon is full. To test this belief, we use a 50-year data set of 38.7 million births in France. The signal includes quasi-periodic and discrete components that need to be subtracted. This is done using a non-linear Gaussian least-squares method. It results in residuals with very good statistical properties. A likelihood ratio test is used to reject that the residual means for the 30 days of the lunar month all equal 0 (p-value = 5×10 -5 ): the residuals show very small but highly significant variations in the lunar month due to an increase of births at full moon and the day after. The reason for the very small increase of birth at full moon is not investigated but can be suspected to result from a self-fulfilling prophecy.

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Published online:
DOI: 10.5802/crmath.223
Classification: 62P10
Chambat, Frédéric 1; Fougères, Anne-Laure 2; Elyildirim, Alexandre 3

1 Université de Lyon, ENSL, LGLTPE, CNRS, 15 parvis René Descartes, F-69007 Lyon France
2 Univ Lyon, Université Claude Berndard Lyon 1, CNRS UMR 5208, Institut Camille Jordan, F-69622 Villeurbanne, France
3 Université de Lyon, UCBL, Polytech, 15 Boulevard André Latarjet, F-69100 Villeurbanne, France
     author = {Chambat, Fr\'ed\'eric and Foug\`eres, Anne-Laure and Elyildirim, Alexandre},
     title = {Slightly more births at full moon},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {805--811},
     publisher = {Acad\'emie des sciences, Paris},
     volume = {359},
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Chambat, Frédéric; Fougères, Anne-Laure; Elyildirim, Alexandre. Slightly more births at full moon. Comptes Rendus. Mathématique, Volume 359 (2021) no. 7, pp. 805-811. doi : 10.5802/crmath.223.

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