facilitate migration (de Janvry et al. 2015) in the context of economic transformation. Active land markets can furthermore permit the use of land as collateral for credit (Deininger and Goyal 2012).

In many cases, efforts to document individuals’ land rights proved particularly advantageous for women. This is largely because, contrary to in traditional settings where women’s land rights are defined through their informal connections (Goldstein and Udry 2008) and relationships (Jayachandran 2015), formal documents make it easier to formally enforce claims. Consistent with the evidence on the impact of changes in female asset ownership,<sup>2</sup> registering women as land owners has been shown to reduce the need for female guarding labor (Field 2007; Goldstein _et al._ 2018); increase investment especially by female-headed households (Ali _et al._ 2014) and women’s labor force participation (Newman _et al._ 2015); and welfare of future generations (Menon _et al._ 2014). Such impacts were found even if certificates are not transferrable, as in Madagascar (Widman 2014) or if land sales are legally prohibited, as in Ethiopia (Deininger _et al._ 2008; Kumar and Quisumbing 2015; Melesse _et al._ 2018; Muchomba 2017) where investment and empowerment effects have been amplified by family law reform (Kumar and Quisumbing 2015).

Yet, although recent technological developments reduced the costs of formalization by orders of magnitude, running national land registries requires resources, organizational capabilities, and a suitable regulatory framework. The widespread absence of these factors in Africa implies that most land rights in rural areas are administered informally by traditional leaders under customary arrangements (Boone 2019). Such systems prohibit land transfers to unrelated outsiders and guarantee land access for lineage members (Baland and Francois 2005) to prevent destitution (Andolfatto 2002). Appreciation of their risk-sharing benefits and cost advantages has traditionally led experts to view customary systems as the most viable option in many settings (Bruce and Migot-Adholla 1994) and prompted many countries to recognize them in law, though less frequently in practice (Alden Wily 2018).

There is evidence that population growth (Greiner 2017) and demand for land by outsiders (Lentz 2010) can set in motion processes of individualization that may lead to an unmediated co-existence of modern and traditional systems. This co-existence may in turn increase <mark>contestability and insecurity (Eck 2014) and reduce or undermine customary systems’ risk sharing advantages</mark> (Delpierre _et al._ 2019), with negative consequences especially for weaker groups such as migrants and women (Bambio and Bouayad Agha 2018). A first sign of the erosion of such groups’ longer-term rights can be a surge in inheritance-related land disputes that may disproportionately involve women (Deininger and Castagnini 2006). As inheritance rights affect incentives for adopting productivity-enhancing practices (Dillon and Voena 2018), this could

> 2 Such interventions have been shown to decrease consumption of male-favored goods in the household (Wang 2014) and to increase girls’ survival rates (Qian 2008), their anthropometric status (Duflo 2003), and their level of schooling (Deininger _et al._ 2013; Luke and Munshi 2011).

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