摘要:Concerns about harmful environmental impacts are frequently raised in research andpolicy debates about population growth in the hills and mountains of developing countries.Although establishing wildlife corridors and biosphere reserves is important for preservingselected biodiverse habitats, for the vast majority of hilly-mountainous lands, the majorecological concerns are for the sustainability of local production systems and for watershedintegrity. What matters for sustained use of those lands not only is the number of producersbut also what, where and how they produce. Indeed, comprehensive evidence from empiricalresearch indicates that population growth in hills and mountains can lead to landenhancement, degradation, or aspects of both. The evidence can be explained by extending induced innovation theory to addressenvironmental impacts of intensification. Increases in the labor-land endowment ratios ofhouseholds and in local land demand and labor supply make the opportunity cost of landrelative to labor increase. As a result, people use hilly-mountainous land resources moreintensively for production and consumption, thus tending to deplete resources andsignificantly alter habitats. But, at the same time, capital- and labor-intensive methods ofreplenishing or improving soil productivity may become economically more attractive,especially where specific property rights develop.Users will choose production systems that enhance the land if the expecteddiscounted returns are greater than those of systems that degrade the land. In addition topopulation change, other factors—market conditions, local institutions and organizations,information and technology about resource management, and local ecologicalconditions—determine the returns from various production systems. Theoretical argumentsand empirical evidence about these other determinants of land-improving investment andmanagement are examined. The challenge to researchers and policymakers is to help toconfigure microeconomic incentives for production that enhance both the land and the welfareof people in these areas.