Authors: Pacheco, Andrea; Meyer, Carsten;

Many tropical forestlands are experiencing changes in land-tenure regimes, but how these changes may affect deforestation rates remains theoretically and empirically ambiguous, hampering generalizations on the most likely long-term effects of land-tenure policies and interventions. Using Brazil’s uniquely comprehensive compilation of land-tenure data and quasi-experimental study design, we estimated the effects of six alternative tenure regimes on deforestation from 1985-2018. We tested the consistency of these findings across regional-historical contexts by creating quasi-repetitions over 49 spatiotemporal scales. Our results indicated that poorly defined public tenure 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 in remote regions where on-the-ground governance is limited and there are extensive environmental policies. Directly privatizing conservation regimes or indigenous lands, in turn, would likely increase deforestation. Our cross-scale synthesis informs how conservation, titling, and other tenure-intervention policies may align with climate-change, biodiversity, and broader environmental sustainability goals; and are directly relevant to ongoing political debates regarding land privatization and/or protection in Amazonia.