Immigration to the U.S., Seventeenth through Twentieth Centuries
Economic-Demographic Interrelationships
Technology Change and Labor Productivity Growth

"Immigrants and Emigrants: The U.S. Labor Markey, 1920-1940"

"Patterns in Migration in the North Atlantic Basin During the 19th Century"

"Migrant Skills and Earnings"

"The Microeconomic Bases of Learning Curves: World War II Shipbuilding"