If full income increased solely because of an increase in V (other money
income) there would simply be a parallel shift of the opportunity curve to
the right with no change in relative commodity prices. The consumption
of most commodities would have to increase; if all did, hours worked would
decrease, for the total time spent on consumption must increase if the output
of all commodities did, and by equation (7) the time spent at work is inversely
related to that spent on consumption. Hours worked could increase only if
relatively time intensive commodities, those with large y, were sufficiently
inferior.'