[imtringued]

The latter sounds something inspired by Keynes except he predicted a 15 hour work week but the books scenario insists on a 40 hour work week. If engineers work too much they can work less hours and give the remaining hours to another person so that there are more jobs. If the engineers insist on working full time, then what happens is that one engineer does the work of three people which means two people either end up unemployed or they must do pointless busy work so that the engineer's ego isn't broken because he thinks he is some kind of hero overworking himself for the sake of lazy people living on government benefits.

Keynes would say something like, "if there are private interests standing in the way of building housing and the like, then burying bank notes in the ground and making people dig them up would be better than... nothing."