WordNet (r) 3.0 (2006):

unproductiveness
    n 1: the quality of lacking the power to produce [ant:
         productiveness, productivity]

Moby Thesaurus II by Grady Ward, 1.0:

29 Moby Thesaurus words for "unproductiveness":
   absurdity, aimlessness, bootlessness, emptiness, fatuity,
   fecklessness, fruitlessness, futility, hollowness, impotence,
   inanity, ineffectiveness, ineffectuality, inefficacy,
   meaninglessness, nugacity, otiosity, pointlessness, profitlessness,
   purposelessness, rat race, the absurd, triviality, unprofitability,
   unprofitableness, valuelessness, vanity, vicious circle,
   worthlessness