In a recent paper, García-Mainar and Montuenga-Gómez (2005) apply the generalized IV model of Hausman and Taylor to estimate education returns of wage earners and the self-employed in Portugal and in Spain. Our examination reveals several problems which relate to the validity and documentation...

"Using Finnish panel data, we study how entrepreneurs differ from workers in education and income dynamics. We find that workers have higher median income in all educational groups. Without additional controls, entrepreneurs have higher average income with all but undergraduate level of...