In 1842 Lowell textile firms increased weaving productivity by assigning three looms per worker instead of two. This marked a turning point. Before, weavers at Lowell were temporary and mostly literate Yankee farm girls; afterwards, firms increasingly hired local residents, including illiterate and Irish workers. An important factor was on-the-job learning. Literate workers learned new technology faster, but local workers stayed longer. These changes were unprofitable before 1842, and the advantages of literacy declined over time. Firm policy and social institutions slowly changed to permit deeper human-capital investment and more productive implementation of technology.