Reductions in resources and increases in external demands place schools under pressure that can be relieved to some extent by organizational changes. When resources are sufficient, these changes may take the form of technical rationality--that is, decisions concerning policy and practices are made on the basis of neutral, measurable data rather than professional judgments. When resources are not sufficient, districts often turn to corporatist representation, drawing outside groups into the decision-making structure. Both strategies increase organizational certainty by decreasing the extent to which outside interests can assume control over the organization's practices. This report reviews the aspects of organizational theory used to explain educational systems--institutional theory and loose coupling theory--and explains why these concepts support the hypothesis that external pressures would lead to organizational changes of the types found. Particular attention is paid to the problem of legitimizing authority in school organizations and the role of technocratic corporatism in this legitimizing process. The rest of the report describes the study, its methodology, and its findings. Data were drawn from government sources and from the 1976-77 Sustaining Effects Study, a survey of superintendents and principals in over 240 school districts across the country. Tables are included. (PGD)