The Economics of Migration (Vol. II) 2002 HKS Authors See citation below for complete author information. George Borjas Robert W. Scrivner Professor of Economics and Social Policy Citation Borjas, George. "Assimilation, Changes in Cohort Quality, and the Earnings of Immigrants." The Economics of Migration (Vol. II). Ed. Klaus F. Zimmermann and Thomas K. Bauer. Edward Elgar, 2002.