A shift to older businesses, an aging workforce, and certain policy developments contributed to a sharp decline in the fluidity of U.S. labor markets in recent decades, according to research by Steven Davis and John Haltiwanger. The declines cut across states, industries and demographic groups defined by age, gender and education. Younger and less educated workers had especially large declines, as did the retail sector. The authors argue that reduced fluidity has harmful consequences for productivity, real wages and employment.