Perhaps the deficit of happiness can be better explained by one of Peter Thiel's most excellent reductionist observations:

  The countercultural in the '60s was the hippies. You know, we
  landed on the moon in July of 1969. Woodstock started three 
  weeks later, and with the benefit of hindsight, that’s when
  progress ended, and the hippies took over the country. [1][2]

Perhaps, for too long, the left has engulfed and held hostage our cultural ideas of progress and advancement. And perhaps that has imbued us with a certain stripe of ideological stagnation not just in the way we perceive modernity but in also the debilitating influence on how we perceive actual technological progress itself and its relevance to the overall happiness of our society.

Perhaps our dominant leftist culture's 'ideological stagnation index' is the unmeasured metric that could explain why we feel the way we feel despite technological progress.

Thiel on the same topic:

  Today the counterculture is to believe in science and technology.
  You know, our society, the dominant culture doesn’t like science. 
  It doesn’t like technology. You just look at the science-fiction 
  movies that come out of Hollywood — Terminator, Matrix, Avatar, 
  Elysium. I watched the Gravity movie the other day. It’s like you
  would never want to go into outer space. You would just want to 
  be back on some muddy island. And so I think we’re in a world 
  where actually believing that a better future is possible that 
  you can have agency and work towards a better future, that is 
  actually radically countercultural.[1]

[1] Glenn Beck and Peter Thiel On How To Change What's Politically Cool

http://www.youtube.com/watch?v=IER50pX-FuM&t=3m22s

[2] Technology Stalled in 1970

http://www.technologyreview.com/qa/530901/technology-stalled...