The Outcome of the Second World War and Fertility in Advanced Economies: Still Postwar

Preprint of "The Outcome of the Second World War and Fertility in Advanced Economies: Still Postwar" (Shuta Ogura). The English version was submitted to Population and Development Review (Data and Perspectives) on 13 September 2026 and is under review. This record contains the English preprint (preprint_en.pdf), a Japanese version (preprint_ja.pdf), the data file (still_postwar_data.xlsx) and the replication script (recompute.py). Abstract. Among today's advanced economies, the states defeated in the Second World War have low fertility. Weinreb and Johnson-Hanks made this observation for six countries in a conference paper (2013, 2014) not published in a peer-reviewed venue. This paper re-examines it with 2024 data and an explicitly selected set of countries. Countries independent in 1945, outside the Eastern bloc during the Cold War, and classified by UNIDO as high-income industrial economies today are ranked by total GDP in 1938 and admitted one at a time; neutrals form a third group. Within the thirteen countries down to Denmark, mean TFR in 2024 is 1.52 for the six victors, 1.27 for the three neutrals and 1.25 for the four defeated, and every victor is above every defeated country. Extending the set to nineteen countries, the victors' mean advantage remains (+0.18) while the complete separation of ranks ends at Greece. The victors' advantage in group means is the central result; the neutrals resemble the defeated. The paper is descriptive. It does not identify a causal effect, does not control for prewar income per head — on which the defeated group was already the lowest — and does not test the mechanism it posits. Data file (still_postwar_data.xlsx), sheets: README (description of the files and sheets, notes on ties and on series not included); Table1_scan (the candidate countries in the order of total GDP in 1938, with the two claims examined — complete separation of ranks and difference of group means — and permutation p-values at every step); Table2_13countries (the thirteen countries with TFR 2024, growth of real GDP per capita 1990–2025, growth of real wages 2000–2024 and real GDP growth 2024); Candidates (the candidate countries and the reason for exclusion); Raw_levels (the levels from which the growth rates are computed); Sources. The script (recompute.py; Python 3, scipy, openpyxl) recomputes every reported aggregate, the sensitivity variants (15, 19 and 21 countries) and the permutation tests from the data file and checks them against the values in the paper. Sources: World Bank, World Development Indicators; Office for National Statistics (United Kingdom TFR 2024); OECD, Average annual wages (retrieved 13 September 2026); Maddison Project Database 2023 (Bolt and van Zanden 2024; GDP in 1938); UNIDO Country Classification, Edition 2026; U.S. Department of Defense, Defense Manpower Data Center.