Land-tenure regimes determine tropical deforestation rates across socio-environmental contexts

Many tropical forestlands are experiencing changes in land-tenure regimes, but how these changes may affect deforestation rates remains theoretically and empirically ambiguous. Using Brazil’s uniquely comprehensive land-tenure and deforestation data and quasi-experimental methods, we analyzed causal effects of six alternative tenure regimes on deforestation across 49 spatiotemporal scales corresponding to distinct regional-historical contexts. We find that poorly defined public tenure regimes caused increased deforestation relative to any alternative regime in most contexts. Private tenure often reduced this deforestation, but did so less effectively and less reliably than alternative well-defined regimes, except for remote regions where on-the-ground government control is limited and where there are extensive private-actor-targeting environmental policies. Directly privatizing public conservation or indigenous lands, in turn, would almost always increase long-term deforestation. The results of our cross-scale synthesis inform how conservation, titling, and other tenure-intervention policies may align with climate-change mitigation, biodiversity-protection, and broader environmental sustainability goals. They are directly relevant to ongoing political debates about privatizing Amazonian conservation and indigenous lands and, given their high generality across diverse socio-environmental settings, potentially applicable in other tropical forest regions that model their forest policies after those in Brazil.