Task specialization in U.S. cities from 1880-2000

We develop a new methodology for quantifying the tasks undertaken within occupations using 3,000 verbs from around 12,000 occupational descriptions in the Dictionary of Occupational Titles (DOTs). Using micro-data from the United States from 1880-2000, we find an increase in the employment share of interactive occupations within sectors over time that is larger in metro areas than non-metro areas. We provide evidence that this increase in the interactiveness of employment is related to the dissemination of improvements in transport and communication technologies. Our findings highlight a change in the nature of agglomeration over time towards an increased emphasis on human interaction