The Collaborative International Dictionary of English v.0.48:

Equalization \E`qual*i*za"tion\, n.
   The act of equalizing, or state of being equalized.
   [1913 Webster]

         Their equalization with the rest of their fellow
         subjects.                                --Burke.
   [1913 Webster]

WordNet (r) 3.0 (2006):

equalization
    n 1: the act of making equal or uniform [syn: equalization,
         equalisation, leveling]