Richard Bilsborrow, Research Professor, Department of Biostatistics,
Carolina Population Center

November 30, 2000—Dr. Richard Bilsborrow of the Carolina Population Center presented the findings and conclusions of his most recent research—a survey (commissioned by the University of Michigan) of population and human migration trends. Unlike most such research (which has dealt with rural-to-urban migration), Bilsborrow's new work primarily examines rural-to-rural migration in areas ranging from South America to Southeast Asia. The work focuses on (a) the environmental factors that contribute to human migration from one rural location to another, and (b) the effects of this migration on the receiving areas' environment.

Bilsborrow reminded those gathered that, while rural populations are growing at a slower overall rate than urban populations, they are growing nonetheless, particularly in the developing world. This growth will continue to place pressure on rural resources. And even in regions that are experiencing negative population growth, the environmental consequences of migration are often high. While the total population of Brazil's Amazon region is down, for example, the effect of the rural migration that follows logging operations in the area is having a devastating effect on primary forestland.

By synthesizing his own research on rural-to-rural migration with the research of others, Bilsborrow is formulating a theory to measure the role of environmental factors in the decision to migrate. He has already determined that, while economics often drive rural-to-rural migration, environmental factors do come into play for household and communities making the decision to move. Families and communities usually decide to migrate only after attempts at agricultural intensification have failed or the available land has proven too small to feed a growing family size. The resultant extensification of the agricultural frontier is migration's greatest environmental effect—an effect that has been documented from Latin America to Southeast Asia (where expansion of agricultural lands has led to forest loss). One striking example is the case of Indonesia, where the official government supported rural-to-rural transmigration that led to the destruction of 60 percent of that country's forests.

Bilsborrow then went on to discuss two particular case studies: Guatemala and the Ecuadorian Amazon. In Guatemala, a rapidly declining mortality rate and a steady fertility rate led to a high concentration of family members on family lands and an eventual fragmentation of landholdings. An examination of census data revealed that this fragmentation subsequently spurred out-migration to other rural areas (especially to Guatemala's highlands), where new land was then exploited for agricultural use.

In the Ecuador case that Bilsborrow examined, all of the original migrants into one region of the Amazon region had been granted legal land title. At the time of the first survey in 1990, 419 families were settled on individual plots in an area which remained 59 percent forested. By 1999, however, the population had approximately doubled, average land plot size had halved due to subdivision, and the settlers had removed the majority of primary forest cover to make way for agricultural crops.

These examples make clear that rural-to-rural migration has a very definite impact on the environment of the receiving area. Bilsborrow concluded, however, that a great deal more research is necessary (in areas of departure as well as destination) in order to understand the matrix of factors driving such migration.