This study provides a structural model of arbitral decision making that depicts arbitrators as deciding cases by ascertaining the facts, attaching weights to the facts, and combining the facts and weights to form decision elements that determine their decisions. The model further posits that arbitrators’ biographical characteristics affect their decisions by influencing their fact finding and weight assignments. It also allows for arbitrators’ characteristics to have a direct impact on their decisions. A test of the model indicates that the decision elements determine the arbitrators’ decisions but the arbitrators’ characteristics have a limited impact.