This book is a volume in the Penn Press Anniversary Collection. To mark its 125th anniversary in 2015, the University of Pennsylvania Press rereleased more than 1,100 titles from Penn Press's distinguished backlist from 1899-1999 that had fallen out of print. Spanning an entire century, the Anniversary Collection offers peer-reviewed scholarship in a wide range of subject areas.

Founded in 1921 as a separate Wharton department, the Industrial Research Unit has a long record of publication and research in the labor market, productivity, union relations, and business report fields. Major Industrial Research Unit studies as published as research projects are completed. This volume is Study no. 43.