現在読んでいる下記の本の中で、定年退職制度（the mandatory retirement system）に賛成か反対か、というテーマについて論証例が載っていました。こうしたありふれた話題でも、事前に自分なりに考え方を整理しておかないと、短時間で要領を得た意見を述べることが出来ないと思いました。
賛成派の論拠、反対派の論拠は非常に参考になりました。以下の論証はちょっと視点を変えて、「当該企業の直面する環境によって賛否は変わる」という見解を簡単にまとめてみました。
It depends on the environment with which companies are facing faced.
It is useful for IT related companies to adopt the mondatory retirement system because these companies facing rapidly changing technological environment have to cope with the environment. For these companies, skills and experiences of elderly workers are no longer useful, and to train younger employees from scratch is more cost-effective. New technologies such as computers or office automation systems can replace skilled workers, and moreover, these new technologies have become cheaper and readily available.
In contrast, companies facing more stable environment can take advantage of life-time employment. For traditional handcraft companies, accumulated skills and experiences of older workers are real assets, and younger employees can obtain necessary skills from elder workers effectively and efficiently. It is not a new technology but a handmade product which gives competitive advantages to these companies.
（学習記録）
英語で意見を論理的に述べる 技術とトレーニング（ベレ出版） p.101～p.123