In jobs where the cost of effort exhibits increasing differences in separate tasks, automation increases productivity by directly eliminating the automated tasks and indirectly by reducing the marginal cost of non-automated tasks. Here, I report a field experiment rotating supermarket cashiers between conventional (where they scanned and collected payment) and scan-only checkouts. Consistent with increasing differences in separate tasks, at conventional checkouts, cashiers who scanned faster collected payments more slowly. At scan-only checkouts, cashiers scanned 10 percent faster, consistent with lower marginal cost of effort in the non-automated task. The faster scanning was not due to learning, less task-witching, or differential shirking.
Ansprechparterin: Lucy Xiaolu Wang