Revolutionary Transition: Inheritance Change and Fertility Decline

Gay, Gobbi, and Goñi test Le Play’s (1875) hypothesis that the French Revolution contributed to France’s early fertility decline by abolishing impartible inheritance. In 1793, a series of decrees culminating in the Loi de Nivôse (January 6, 1794) abolished testamentary rights and imposed equal partition of assets among all children — partible inheritance — across France, overriding the mosaic of local customs and written laws that had governed inheritance in the Ancien Régime.

The paper’s central argument is that this reform reduced the economic incentive to have children through indivisibility constraints in agricultural land. Under impartible inheritance, land passed to a single heir undivided, keeping plots above the subsistence productivity threshold even at high fertility. Under partible inheritance, each additional child fragments the land further, potentially pushing plots below the minimum productive size, so households face a strong incentive to limit fertility. A Stone-Geary production function with a minimum land threshold L̄ formalizes this mechanism: when landholdings fall in the binding range (L̄ < L < L̃), fertility is strictly higher under impartible than under partible inheritance.

The authors construct the first complete map of inheritance rules across France’s 435 judicial districts as of 1789, classifying each along two dimensions: partible versus impartible, and whether women were included or excluded. This atlas draws on Brette’s (1904) Atlas des Bailliages and the Nouveau Coutumier Général (Bourdot de Richebourg 1724), covering 141 distinct customs. Treatment is defined as municipalities under impartible inheritance before 1793 whose system was altered by the reforms; control municipalities were already under partible inheritance.

The main identification strategy is a difference-in-differences (DD) design comparing women with varying lengths of remaining fertile years after 1793 — from 0 for women aged 40+ at the reform to 25 for women aged 15 or younger — across treated and untreated municipalities. This is augmented by a regression-discontinuity difference-in-differences (RD-DD) design exploiting sharp discontinuities at judicial district borders. Two independent datasets are used: the Enquête Louis Henry (34,812 women in 39 rural municipalities, family-reconstitution method) and Geni.com crowdsourced genealogies (11,649 women across 2,966 locations after the Blanc 2023 horizontal restriction).

Each additional fertile year of exposure to the 1793 reforms reduced completed fertility by approximately 1 percent. Over the full 25-year fertile cycle, this corresponds to a reduction of roughly 0.7 children, or 24 percent relative to the pre-reform mean of 2.92 surviving children in treated areas. This magnitude equals the entire pre-reform fertility gap between impartible- and partible-inheritance areas (2.9 versus 2.2 children), meaning the reforms closed this gap entirely. DD and RD-DD estimates are similar and not statistically distinguishable from each other, and results replicate across both datasets. Results hold on both the extensive margin (childlessness) and intensive margin (fertility of mothers).

The mechanism is most relevant where smallholder landownership is widespread. France — where 40–80 percent of households owned land at the eve of the Revolution — meets this condition. England and Prussia, with more concentrated landownership, would not be expected to show the same response because the indivisibility constraint would not bind even after partition.

Q: What was France’s inheritance system before the Revolution, and how heterogeneous was it? A: Before 1793, inheritance was governed by 141 distinct customary and written laws applied within 435 judicial districts. The country was broadly divided between the customary-law north (Pays de droit coutumier) and the Roman written-law south (Pays de droit écrit), with substantial local variation within regions. Systems ranged from strictly partible (equal division among all offspring) to impartible (primogeniture, ultimogeniture, or unigeniture). Systems also varied in whether women could inherit or received only a dowry. This geographic variation — rooted in the laws of Germanic peoples after the fall of Rome in 476 CE — is exogenous to late eighteenth-century economic conditions and provides the identifying variation for the paper.

Q: What exactly did the 1793 reforms change, and were they enforced? A: The Loi de Nivôse an II (January 6, 1794) abolished testamentary rights entirely and mandated equal partition of assets among all children, including women, throughout France. The reforms came unexpectedly — only 8 of 571 cahiers de doléances analyzed by Goy (1988) mentioned inheritance — and were motivated by the equality principle, legal unification, and the fear that revolutionary sympathizers would be disinherited (Lataste et al. 1901). Offspring quickly asserted their new rights, and by the late 1790s inheritance disputes were the most common cases before family tribunals (Desan 1997; Poumarède 2011).

Q: What is the model’s core mechanism linking inheritance reform to fertility decline? A: The model uses a Stone-Geary production function with a minimum land threshold L̄ below which output falls to zero. Under impartible inheritance, land passes undivided to a single heir, keeping the farm above L̄ regardless of family size. Under partible inheritance, each child receives an equal share, so adding children risks fragmenting plots below L̄ — a powerful incentive to limit family size. The fertility gap between impartible and partible households is at its maximum when landholdings fall in the intermediate range (L̄ < L < L̃) where the constraint is binding. As land size increases, the constraint becomes less binding but the positive fertility differential persists.

Q: What is the paper’s main quantitative estimate of the reform’s effect on completed fertility? A: Each additional fertile year of exposure to the 1793 reforms reduced completed fertility by approximately 1 percent. Over the full 25-year fertile cycle (ages 15–40), this implies a reduction of roughly 0.7 children, or 24 percent relative to the pre-reform mean of 2.92 surviving children in treated areas. This is nearly identical to the pre-existing fertility gap between impartible- and partible-inheritance areas (0.7 children: 2.9 versus 2.2 surviving children), implying the reforms effectively eliminated the fertility differential.

Q: Are the DD and RD-DD estimates consistent with each other, and do both datasets agree? A: Yes. The DD and RD-DD estimates are similar and not statistically different from each other. The RD-DD design compares women born close to judicial district borders where inheritance rules differed, before and after 1793, exploiting the sharp spatial discontinuity at those borders. Consistency across these two designs — which rely on different identifying assumptions — strengthens causal interpretation. Results are also consistent across the Enquête Louis Henry (family-reconstitution) and Geni.com (crowdsourced genealogies) datasets, which are produced by fundamentally different methodologies.

Q: How do the authors verify the parallel trends assumption? A: Figure 6 shows that for cohorts who completed their fertile cycle before 1793, fertility trended downward in parallel across partible- and impartible-inheritance areas: a constant gap of approximately 0.7 children was maintained from women born in the early 1700s (3 versus 2.3 children) through women born in the early 1750s (2.7 versus 2.0 children), the last cohorts to complete fertility before the reforms. The convergence — from 0.7 to 0 children — only begins among cohorts fertile after 1793. The authors also include flexible trend controls interacted with municipality-level religiosity, political support for the Revolution, proximity to administrative centers, and wheat prices, and confirm the main estimate is robust.

Q: What role did the extension of inheritance rights to women play? A: The extension of rights to women was a companion mechanism distinct from abolishing impartible inheritance. Beyond increasing the number of heirs (which directly reduces land per heir), the right to inherit improves a woman’s outside option and postpones entry into marriage, following de Moor and van Zanden (2010). The DD and RD-DD estimates suggest that including women in inheritance and abolishing impartible inheritance had similar effects on fertility. The paper treats these as separate but reinforcing channels.

Q: How do the authors address potential confounders — mortality, migration, and economic conditions? A: On mortality: child mortality did not evolve differently after 1793 across areas with different inheritance rules (Appendix Table A3), and baseline adult mortality (age at death, probability of dying before completing the fertile cycle) was balanced across treated and control areas (Table 1). On migration: the authors explicitly rule out that results are driven by migration. On economic conditions: municipality-specific decade-average wheat prices (Ridolfi 2019) are included as controls for local Malthusian dynamics, and results are robust to their inclusion.

Q: What do the balance tests show? A: Panel A of Table 1 shows that before the reforms, areas with impartible versus partible inheritance were balanced on 9 of 11 individual-level characteristics — including husband and wife age at death, probability of dying before completing the fertile cycle, probability that parents-in-law were alive at marriage, literacy, data accuracy, and age at marriage. The only systematic pre-reform difference was fertility itself (0.7 children). Municipality-level climatic variables, soil suitability, and proxies for mortality uncertainty were also balanced. This is consistent with the origins of these systems in post-Roman Germanic law, which are unrelated to late eighteenth-century economic conditions.

Q: What robustness checks are reported? A: The authors report: (1) permutation tests reshuffling treatment exposure across women and municipalities; (2) non-linear treatment effects across cohorts, showing the heterogeneity required to explain away the baseline estimate is implausibly large per de Chaisemartin and d’Haultfoeuille (2020); (3) exclusion of outlier municipalities; (4) a placebo test for cohorts who completed their fertile cycle before 1793; (5) robustness to alternative sample definitions, treatment definitions, outcome variables, and control groups; (6) Cummins (2020) first-name repetition technique to correct for under-reported child deaths in Henry; (7) terrain characteristics including climatic and soil suitability (Galor and Özak 2016) and ruggedness (Nunn and Puga 2012); (8) for RD-DD: alternative bandwidths, running variable specifications, kernel functions, samples, and border-segment fixed effects. All checks support the main finding.

Q: Why did France experience a fertility decline from inheritance reform while other countries with similar reforms did not? A: The model rationalizes this through landownership structure. The fertility-reducing mechanism operates through indivisibility constraints that bind only when landholdings are small and fragmented — as in France, where 40–80 percent of households owned their land and plots were small. Where landownership is concentrated (England, Prussia), land per heir remains above L̄ even after partible division, so the indivisibility constraint is non-binding and fertility is unaffected by the reform. This provides a structural reason why France’s particular agrarian structure made it uniquely susceptible to this mechanism.

Q: What is the broader historical significance for understanding France’s early demographic transition? A: France’s fertility decline began roughly 50 years before industrialization, making it anomalous relative to standard quantity-quality tradeoff theories linking fertility decline to technological progress and rising returns to human capital. The 1793 reforms provide a legal-institutional explanation for the sharp post-Revolution acceleration visible in Figure 1, which is difficult to attribute to slowly-evolving cultural factors or human capital considerations not yet operative. The estimates imply the reforms brought large impartible-inheritance areas to the low-fertility regime that already characterized partible-inheritance areas, thus sharply accelerating the national transition.

Impartible inheritance: A system under which parents could designate a single heir (through primogeniture, ultimogeniture, or unigeniture) to receive the bulk of the family estate, preventing fragmentation of wealth; in pre-revolutionary France this was associated with extended family households and higher fertility (2.9 surviving children on average) relative to partible areas (2.2).

Partible inheritance: A system under which family wealth was divided equally among all offspring upon death; in the paper’s model this creates an incentive to limit fertility to prevent land fragmentation below the subsistence productivity threshold L̄.

Indivisibility constraint (land threshold L̄): In the Stone-Geary production function, a minimum land input below which agricultural output falls to zero; this is the mechanism through which partible inheritance generates fertility-limiting incentives, since dividing a small plot among many heirs risks crossing L̄ into zero production.

Difference-in-differences (DD) exposure design: The paper’s main identification strategy, using remaining fertile years after 1793 as a continuous treatment-intensity variable (0 for cohorts past fertility at the reform date, up to 25 for cohorts entirely within their fertile years), compared between treated municipalities (impartible → partible) and control municipalities (already partible).

Regression-discontinuity difference-in-differences (RD-DD): An augmented design exploiting the sharp geographic discontinuity at borders between judicial districts with different pre-reform inheritance rules, comparing outcomes on both sides before and after 1793, to address smooth unobserved confounders.

Completed fertility (net): The number of children surviving to age six, preferred over total births because child mortality before 1800 was high (1–1.5 children per mother did not survive to age six per Houdaille 1984), making net fertility the more economically meaningful measure for inheritance and bequest decisions.

Horizontal restriction: A sampling correction applied to crowdsourced genealogical data (Blanc 2023a) that retains an observation only if at least one of the four preceding generations has more than one recorded offspring, correcting for the over-representation of single-child families that arises because Geni users tend to record direct ancestors rather than collateral relatives.