The feasibility and potential relevance of comprehensive planning models for postsecondary education are examined, focusing on the two most widely discussed models of this type: (1) the Postsecondary Education Financing Model (PEFM) of the National Commission on the Financing of Postsecondary Education, and (2) the Federal Planning Model (FPM) of the National Center for Higher Education Management Systems, Western Interstate Commission for Higher Education. The broader context within which such analyses are pursued are considered, identifying the important dimensions of the postsecondary education sector that must be captured by any prototype model. An attempt is made to provide an alternative strategy for enhancing understanding of the postsecondary education sector and the functional effectiveness of both public and private policies. Areas in which potential students and institutions directly interact include the following: admission policies, standards of academic performance, responsiveness of academic programs to labor market conditions, and pricing and financial aid policies. Important aspects of internal organization include faculty composition and the general mix of activities undertaken by faculty. The FPM includes a student demand model, which is short-run, comparatively static, and positive, and an institutional model that has both long-run and short-run and both static and dynamic components. FPM is essentially a model of a single institution. The PEFM predicts changes in the future configuration of the postsecondary system from National Center for Education Statistics benchmarks induced by specific policy actions. It is concluded that each model has major weaknesses at both a conceptual level and at the level of empirical implementation. (SW)