Because of the significant wage differential between Brazil and Japan,

“Because of the significant wage differential between Brazil and Japan, nikkeijin who work as unskilled factory workers in Japan are able to earn five to ten times their middle-class Brazilian incomes.”

This statement clearly supports the Neoclassical Economics Theory of International Migration because it mentions that it was the wage difference that worked as the motive for nikkeijins to migrate to Japan and work as unskilled factory workers. The statement further clarifies that nikkeijins were able to earn five to ten times higher than they could earn being the Brazilian middle-class. Therefore, this statement refers to and strengthens the Neoclassical Economics theory of migration.