A passenger mix model (PMM) is used by airlines to find out how many passengers will fly on a fleet schedule. There are numerous ways of modeling passenger mix models and this report studies a share based passenger mix model, proposed by Sabre, and tests its efficacy against a deterministic linear program (DLP) passenger mix model. A DLP passenger mix model cannot recapture spilled passengers and requires iterations of the same model to recapture passengers. In order to eliminate the iterative nature of the DLP model Sabre proposed a new model which eliminates iterations for recapturing passengers. This report studies the proposed share based passenger mix model and compares it with the DLP model in terms of traffic allocation and speed of solution. It is found that the share based model allocates traffic in the same manner as the tried and tested DLP model. / text