We investigate the ion-ion pair association equilibrium in the hard sphere ionic fluid as predicted by several Debye-Huckel-based theories. The degree of dissociation is examined in a pairing theory based on Ebeling's definition of the association constant, and in extensions of this theory for ion pair-free ion interactions by Fisher and Levin, and ion pair-ion pair interactions by Weiss and Schroer. The effect of an increase of the dielectric constant on the degree of dissociation is studied. In all cases, minima of the density-dependent degree of dissociation along isotherms are found at low ionic density, at least over part of the temperature range. The loci of these minima in the temperature-density plane are calculated. The results are compared with conductivity data. We discuss a possible resemblance of the system's behavior in a region in which the degree of association changes rapidly with a tricritical scenario, in which a line of second-order insulator-conductor phase transitions intersects the coexistence curve.