Korea's first female president, Park Geun-hye, takes up office today.  This is a big step forward for the country, and for the wider political scene.   I've never been to Korea, but I've been thinking of using it as a case study for the Paula Principle, for the folllowing reasons. Koreans have made extraordinarily rapid educational progress over the past two decades.   15-20 years ago they were near the foot of the OECD league table on achievement at secondary school;  now they are at or around the top. It is a truly remarkable transformation. Their tertiary system has expanded in consequence, very rapidly, so that there are now large numbers of…