Summary: Experiments were conducted with respect to two classifier system mechanisms: the bid competition and the use of classifier specificity in bidding and payments. The experiments employed a simplified classifier system and so may not accurately reflect the behavior of the standard system. Nevertheless, the results indicated that, in general, (1) specificity should not be factored into amounts deducted from a classifier’s strength, (2) the bid competition does not improve performance and does not encourage default hierarchies, and (3) default hierarchies will form under a somewhat different algorithm than the standard one.