Education and Income in the Early 20th Century: Evidence from
the Prairies We present the first estimates of the returns to
years of schooling before 1940 using a large sample of men and
women, employed in a variety of sectors and occupations, from
the Iowa State Census of 1915. We find that the returns to a
year of high school, and to a year of college, were substantial
in 1915 - about 11 percent for all males and in excess of 12
percent for young males. Some of the return to years of high
school and college arose because more education allowed
individuals to enter lucrative white-collar jobs. But we also
find sizable educational wage differentials within the white-
and blue-collar sectors. Returns to education above the 'common
school' grades were substantial even within the agricultural
sector. Given the high overall rate of return to secondary
schooling, it is no wonder that the 'high school movement' took
root in America around 1910, even in agricultural areas such as
Iowa. Census data for 1940, 1950, an