Administrations in public education can do little besides struggle to balance the number of needed and available teachers. Conventional student–teacher ratios perpetuate trends and are unfit for policy making. Besides lacking a suitable alternative, the Portuguese government was concerned that declining birth rates might make tenured teachers redundant over time. Their hiring policies became gradually more conservative and less transparent, and grievances escalated. An SD model provided rigorous estimates for the number of public grade and secondary teachers needed in each Portuguese school district, per teaching group (science, English, etc.). The model combined a structure of three goal‐seeking aging chain arrays. Its results were used to quantify and allocate tenured teacher vacancies in 2015. The model showed that redundancy concerns were unfounded and hiring for all vacancies was justifiable in the future. These results might have been difficult to anticipate by human decision makers because of the delays involved.

中文翻译：

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公共政策制定中的老龄化影响

公共教育管理部门除了努力平衡所需和可用教师的数量之外，无能为力。传统的师生比例可以长期保持趋势，不适合制定政策。葡萄牙政府除了缺乏合适的替代方案外，还担心出生率下降可能导致终身任用教师随着时间的流逝而变得多余。他们的聘用政策逐渐变得更加保守，透明度越来越低，委屈程度不断上升。SD模型提供了每个教学组（科学，英语等）每个葡萄牙学区所需的公职和中学教师人数的严格估计。该模型结合了三个寻求目标的老化链阵列的结构。其结果用于量化和分配2015年的终身教师职位空缺。该模型表明，冗余的担忧是没有根据的，将来所有空缺的招聘都是合理的。由于所涉及的延迟，人类决策者可能难以预期这些结果。