Ecological perturbations can either be necessary for maintaining tropical forest diversity or responsible for its decline, depending on the scale, nature, and frequency of the disturbance. Anthropogenic disturbances such as logging and subsistence agriculture may promote the establishment of nonnative, invasive plant species, potentially affecting forest structure and diversity even long after ...

Intra-Household Labor Supply, Migration, and Subsistence Constraints in a Risky Environment: Evidence from Rural El Salvador We use panel data from El Salvador to investigate migration and the intra-household allocation of labor as a strategy for coping with uninsured risk. Consistent with a model of a farm household with a binding subsistence constraint, we show that adverse agricultural produ...

The Malthusian theory of evolution disregards a pervasive fact about human societies: they expand through con ict. When this is taken account of the long-run favors not a large population at the level of subsistence, nor yet institutions that maximize welfare or per capita output, but rather institutions that generate large amount of free resources and direct these towards state power. Free res...

Intensive size-selective harvesting can drive evolution of sexual maturity at smaller body size. Conversely, prehistoric, low-intensity subsistence harvesting is not considered an effective agent of size-selective evolution. Uniting archaeological, palaeontological and contemporary material, we show that size at sexual maturity in the edible conch Strombus pugilis declined significantly from pr...

North American archaeologists have spent much effort debating whether Early Paleoindian foragers were specialized hunters of megafauna or whether they pursued more generalized subsistence strategies. In doing so, many have treated the foraging practices of early North Americans as if they must have been uniform across the continent, even though others have pointed out that adaptations appear to...

OBJECTIVES Marriages among kin have the dual effect of both increasing average group relatedness as well as reducing the total number of kin by eliminating more genealogically and geographically distant individuals from kinship networks. Marriage decisions therefore face a tradeoff between density of kin, or formation of intensive kinship systems, and the diversity of kin, or extensive kinship ...

Standard economic theory suggests that one-time business grants can have at most temporary effects, and accordingly, policies to increase incomes of the self-employed in developing countries typically rely on sustained engagement. In contrast, we found long-lasting impacts from one-time grants given in a randomized experiment to subsistence firms. Five years after we gave $100 or $200 to 115 of...

The Malthusian theory of evolution disregards a pervasive fact about human societies: they expand through con ict. When this is taken account of the long-run favors not a large population at the level of subsistence, nor yet institutions that maximize welfare or per capita output, but rather institutions that maximize free resources. These free resources are the output available to society afte...

The Malthusian theory of evolution disregards a pervasive fact about human societies: they expand through con ict. When this is taken account of the long-run favors not a large population at the level of subsistence, nor yet institutions that maximize welfare or per capita output, but rather institutions that maximize free resources. These free resources are the output available to society afte...