[taejo]

This is an instance of Jevon's paradox (http://en.wikipedia.org/wiki/Jevons_paradox): making a process more efficient in terms of resource requirements (in this case labour), causes the process to become more profitable and grow, therefore using more rather than less of the resource.

[taejo]

This is assuming sufficiently elastic demand (i.e. there is unfulfilled demand at the old price).