Red Mars by Kim Stanley Robinson

"... If you don't go ahead and assign values to a number of non-physical things, then electricians and plumbers and other infrastructure workers would always rate as the most productive of society, while artists and the like would be seen as contributing nothing at all."

"sounds about right to me," John joked, but Vlad and Marina ignored him. 

"Anyway, that's a large part of what economics is - people arbitrarily, or as a matter of taste, assigning numerical values to non-numerical things. And then they pretend that they haven't just made the numbers up, which they have. Economics is like astrology in that sense, except that economics serves to justify the current power structure, and so it has a lot of fervent believers among the powerful."

p. 269

Economics as astrology - yeah. I always thought the advice I got from my astrologer was better han the advice that I got from my broker. And I never thought that either one had much of a grounding in reality.