The Collaborative International Dictionary of English v.0.48:

Scarceness \Scarce"ness\, Scarcity \Scar"ci*ty\, n.
   The quality or condition of being scarce; smallness of
   quantity in proportion to the wants or demands; deficiency;
   lack of plenty; short supply; penury; as, a scarcity of
   grain; a great scarcity of beauties. --Chaucer.
   [1913 Webster]

         A scarcity of snow would raise a mutiny at Naples.
                                                  --Addison.
   [1913 Webster]

         Praise . . . owes its value to its scarcity. --Rambler.
   [1913 Webster]

         The value of an advantage is enhanced by its
         scarceness.                              --Collier.
   [1913 Webster]

   Syn: Deficiency; lack; want; penury; dearth; rareness;
        rarity; infrequency.
        [1913 Webster]

WordNet (r) 3.0 (2006):

scarcity
    n 1: a small and inadequate amount [syn: scarcity,
         scarceness] [ant: abundance, copiousness,
         teemingness]

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "scarcity":
   absence, chinchiness, chintziness, dearth, deficiency, exiguity,
   fewness, inadequacy, inadequateness, infrequence, infrequency,
   insufficiency, lack, meagerness, miserliness, need, niggardliness,
   occasionalness, paucity, poverty, rareness, rarity, restrictedness,
   scant, scant sufficiency, scantiness, scarceness, scrimpiness,
   seldomness, shortage, skimpiness, slowness, smallness, sparseness,
   sparsity, stinginess, stringency, thinness, tightness,
   uncommonness, underage, unfrequentness, uniqueness, unusualness,
   want