If you make an infographic colorful enough and confusing enough, people won't pay attention to how absurd your methodology is. That seems to be the theory motivating this chart, posted by Alexander Russo and originally developed by the futurejournalismproject:
A few objections. First, it simply can't be the case that teachers in the UK only work 15.6 weeks a year, which is what the chart implies (~625 hours / 40 hours). In fact, the Association of Teachers and Lecturers, a teacher union there, claims British educators are overworked and average 50 hour weeks much of the year. There's clearly a fundamental problem with the underlying data for hours worked ? one of Russo's commenters suggests contact hours, not work hours, are being measured.
Second, salary divided by GDP per capita is not a useful measure of how well a profession is compensated, because it suggests teachers in the US deserve the same fixed share of economic output that teachers in other countries command. In doing so, the chart compares apples to oranges ? Korea's teachers are drawn from the top 5% of their class in high school and go through highly selective programs (the same story prevails in Finland). Korea also has a student-teacher ratio of 30:1 and math teachers making $4M a year in virtual education:
South Korea is able to pay teachers high starting salaries because it employs relatively fewer than other nations. As a result, the student-teacher ratio in South Korea is 30:1, compared to the OECD average of 17:1.
It's a smart tradeoff because studies show that teacher quality has significantly more impact on student outcomes than class size. Dollar for dollar, it's better to attract a small number of outstanding educators with high starting salaries than to attract a large number of mediocre ones with lower starting salaries ? even if that means having a high student-teacher ratio.
The moral of the story? Beware of drawing simple conclusions from misleading infographics. They can conceal much more than they reveal.