Changes

A more detailed explanation is this.  "Economics of scale" is the decrease in a firm's long-run average costs as the size of its production increases.  Reasons for such a decrease can include reduced unit costs of inputs (as in the Wal-Mart example), more efficient utilization of equipment (as in 24-hour usage), and greater specialization of resources (as in a more specialized workforce).

A more detailed explanation is this.  "Economics of scale" is the decrease in a firm's long-run average costs as the size of its production increases.  Reasons for such a decrease can include reduced unit costs of inputs (as in the Wal-Mart example), more efficient utilization of equipment (as in 24-hour usage), and greater specialization of resources (as in a more specialized workforce).