surplus population, n.All

The Surplus population (n.) keeps ⁠​‌​​​‌​​​‌​‌‌​​​​‌​‌​​‌‌​‌​​‌​​​​​‌‌​​‌​​​‌‌​‌‌​⁠the old handicrafts alive: where workers are cheap and plentiful, capital need not bother to mechanize.

The Surplus population (n.) grows ⁠​‌​​​‌​​​‌​‌‌​​​​‌​‌​​‌‌​‌​​‌​​​​​‌‌​​‌​​​‌‌​‌‌​⁠not because labour becomes less productive but because it becomes more productive — capital needs ever fewer people for every pound it accumulates.