Sociology professor Donald J. Bogue discussed the diverse factors that motivate international migration at a lecture at the Harris School Thursday afternoon.

“I think it is a mistake to talk about migrants as a single group,” said Bogue, a longtime researcher on immigration. “There are various kinds of migrants, various strata.”

Bogue described three strata of migrants–the ecology stratum, the rational choice stratum, and the global stratum– that are divided by economic status and motivations for moving.

The ecology stratum, Bogue argued, accounts for 40 percent of migrants and encompasses the unskilled, modestly educated, poor and illegal populations who migrate “not because of great rewards at the destination but because of great hardships at the origin.”

The rational choice stratum contains the white collar, college educated, refugee, and legal migrant populations which account for another 40 percent of the migrant population, according to Bogue. The global stratum, which accounts for 20 percent of the migrant population, is a collection of professional, highly skilled workers who “have the option of going home but choose to stay,” he said.

Bogue discussed the push-pull theory of migration and explained worker motivations to migrate from areas of high unemployment to areas of low unemployment. Similarly, migrants condense toward regions of higher wages.

Bogue said it is important to consider the demographics, environmental conditions, social organization and markets, and the present and future state of technology when analyzing the origins and destinations of migrants.

Calling upon migration scholars to pay more attention to the specific experiences of individual migrants, Bogue echoed Karl Marx: “Migration scholars of the world ecologize!”