ABSTRACTWe examine the implications of migration and insecure property rights to land use and deforestation in tropical frontier forests. Three forms of property rights risks are introduced to basic land-use forms. Illegal logging risk is associated with forest plantations, a land expropriation risk affects land in agriculture and plantation forestry, and illegal logging risks threaten native forest land. Public and private landowners can reduce these risks by employing costly enforcement effort. We show how that migration, expropriation, and illegal logging risks lead to deforestation by promoting agricultural expansion, and illegal logging. Higher public enforcement reduces illegal logging, but higher private enforcement may or may not reduce deforestation depending on migration pressures. Higher timber prices have an ambiguous effect on deforestation, but an increasing value of non-timber benefits decreases or leaves deforestation unchanged depending on the incentive structures of illegal loggers.