It is against the backdrop of both theory and practice that the foliowing remarks are presented. Their intention is not so much to suggest new techniques of models as to assign priorities to certain aspects of the process of plan development. The comments are therefore addressed at an operational levei. But they do not preclude cotinuing research upon formal models of the input-output variety or the llke. Yet it is also appropriate to add that such modeis may be more appropriate and efficient in instances where control over flows and prices is much more centralized than in cases in which the price mechanism itself performs many of the allocative functions.21 p.