日本ではPhDの一般的な評価が低く、そのために就職にも有利とならず、博士の就職難問題などの原因になっているという話があります。
実際、大企業でも研究職の大半が修士卒以下だというのは先進国では珍しいのに対して、欧米ではPhDを持っていないとアカデミックでも企業でも一人前の研究職とは認められないようです。
しかし先日読んだThe Economistの記事、“The disposable academic: Why doing a PhD is often a waste of time”では、欧米でもPhDの評価が低いと論じています。平均年収の話もあり、説得力があります（例えば修士卒と博士卒では給料の差がほとんどなく、学部によっては逆転するそうです）。以下に抜粋します。
海外でもPhDは奴隷のように働かされている
ドクターコースを終え、企業に就職したドイツ人の同僚もこんなことを言っていました。安い労働力としてこき使われ、長時間労働と低賃金、そして将来への不安は同じようです。
One thing many PhD students have in common is dissatisfaction. Some describe their work as “slave labour”. Seven-day weeks, ten-hour days, low pay and uncertain prospects are widespread. You know you are a graduate student, goes one quip, when your office is better decorated than your home and you have a favourite flavour of instant noodle.
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But universities have discovered that PhD students are cheap, highly motivated and disposable labour. With more PhD students they can do more research, and in some countries more teaching, with less money.
PhDコースで教える内容は就職に結びつかない
PhDコースはアカデミア職に就く人のためにデザインされていますが、アカデミア職の空きが足りないようです。また企業が求めるスキルは身に付いていないようです。
PhDが不足しているのは新興国だけのようです。
There is an oversupply of PhDs. Although a doctorate is designed as training for a job in academia, the number of PhD positions is unrelated to the number of job openings. Meanwhile, business leaders complain about shortages of high-level skills, suggesting PhDs are not teaching the right things.
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America produced more than 100,000 doctoral degrees between 2005 and 2009. In the same period there were just 16,000 new professorships.
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in Canada, where the output of PhD graduates has grown relatively modestly, universities conferred 4,800 doctorate degrees in 2007 but hired just 2,616 new full-time professors.
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Only a few fast-developing countries, such as Brazil and China, now seem short of PhDs.
アメリカのPhDコースに新興国の学生が集まるのは低賃金だから
確かにこのような見方もありますね。
In some countries, such as Britain and America, poor pay and job prospects are reflected in the number of foreign-born PhD students. Dr Freeman estimates that in 1966 only 23% of science and engineering PhDs in America were awarded to students born outside the country. By 2006 that proportion had increased to 48%. Foreign students tend to tolerate poorer working conditions, and the supply of cheap, brilliant, foreign labour also keeps wages down.
PhDを取っても給料は高くならない
英国でのデータ；
- 大卒 vs. 高卒 : 14%高い給料
- 大卒 vs. 修士卒 : 23%高い給料
- 大卒 vs. 博士卒 : 26%高い給料
つまり修士卒に比べて3%しか高い給料は得られないという話です。
しかも数学と計算機、社会科学と言語学ではこの差は消滅します。さらに工学や技術、建築と教育では逆転し、修士卒の方が高い給料が得られています。
In some subjects the premium for a PhD vanishes entirely. PhDs in maths and computing, social sciences and languages earn no more than those with master’s degrees. The premium for a PhD is actually smaller than for a master’s degree in engineering and technology, architecture and education. Only in medicine, other sciences, and business and financial studies is it high enough to be worthwhile.
Naofumi Kagami 