Part III of the study describes a model for completing the cost assessment (justification) process by accounting for the fixed joint costs; a "fair" and equitable mechanism is developed in the context of game-theoretic approach. An n-person game is constructed in which the "players" are the institutions served by the library, but whose characteristic function reflects the initial set-up costs of any group of institutions if a library were to be constructed to meet their requirements. A Shapley value solution to the game is used to derive a hierarchy of institutions which may be employed in allocating the fixed portion of the annual joint costs of operating the library system to determine the institutionally based fees. The model is applied to data from HAM-TMC Library and the proportion of fixed operating costs to be allocated to each institution is calculated. The main theoretical aspects of the game relevant to this study and selected references are appended. (Author/JPF)