Glad to share a new paper, “Reproductive responses to revolution and repression in Finland, 1917–1919”, now open access in The History of the Family!
doi.org/10.1080/1081... 1/11
The paper uses monthly data on sex ratios at birth (SRB) to study how the population of Finland responded to a series of extraordinary events at the grass roots level. During the research period, the country experienced major economic, political and social instability. 2/11
SRB has a standard reference value of 105-106 boys per 100 girls. Material and/or mental stress causes miscarriages which are male biased, leading to a fall in SRB. However, circumstances increasing coital frequency raise the likelihood of conceiving male children, therefore elevating SRB. 3/11
The events in 1917-1919 included an Imperial revolution in Russia, a Civil War in Finland and its aftermath, and a mass release of prisoners. They also included declaring independence, a crisis in food supply, the Spanish Flu pandemic, and periods of social unrest and collapse in policing. 4/11
Jan 30, 2026 05:05Using time series data from 1878 to 1938, the article analyses the timing and nature of major deviations in SRB. Annual data on 1918 is puzzling, as it shows no drop in SRB during what, by many indicators, was the worst year in early 20th century Finnish history. Monthly data unpacks this. 5/11
While there was a predictable drop in SRB at the culmination of the Civil War in May 1918, there was an exceptional peak in SRB in January 1918. This was nine months after the March revolution of 1917 in the Russian Empire, causing widespread celebration, gatherings and disruption of norms. 6/11
The finding suggests that the March revolution led to increased coital frequency. A similar peak with slight build-up is noticeable in May 1919, which matches the mass release of Red prisoners towards late summer 1918. Previous literature shows similar results around wars and demobilisations. 7/11
The results are based on time series regressions controlling for seasonality (month effects) and autocorrelation (Newey-West standard errors). They are robust to changing the reference period and controlling for nonmarital births. A Supplement analyses potential registration issues. 8/11
The findings suggest events directly related to political upheavals and violence engendered embodied and behavioral responses that left traces in monthly reproductive statistics. In contrast, economic stress, national independence or the pandemic left no similar traces of short-term response. 9/11
While strict causality cannot be proven with the data, the analysis recalibrates the perceived importance of different milestones in national historiography. Reproductive statistics can be used to study the embodied reactions and popular sentiment surrounding major historical events. 10/11
The article is a part of a Special Issue on “Environmental stressors across time”. Thank you to the editors, referees and everyone who commented on earlier drafts! The work was initiated while visiting the LSE in 2021 and has been supported by the Research Council of Finland. 11/11
