Immigration to the U.S., Seventeenth through Twentieth Centuries
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"