摘要：To design effective policies for rainforest
conservation in shifting cultivation systems, it is crucial to have a better understanding
of shifting cultivators’ decision making. This paper develops a unified dynamic
farm model of shifting cultivation, addressing two lacunae in extant
theoretical works: taking into account differences between primary and secondary
forests and potential roles of on-farm soil conservation. The model unifies
shifting cultivator’s decisions about primary-forest clearing, forest
fallowing, and on-farm soil conservation by incorporating new soils acquired
from cleared primary/secondary forest land into on-farm soil dynamics. I
examine how three distinct policies—forest protection (e.g., protected areas),
fallow management (e.g., improved fallow), and on-farm soil management (e.g.,
biochar in Amazonia)—alter primary-forest
clearing (deforestation) and fallow length. The analysis reveals that although
all three policies reduce deforestation, only on-farm soil management leads to
longer fallow, i.e., sustainable
secondary fallow forest.
