@jasonacollins If slightly-below-average member of high-IQ country moves to low-IQ country, both means can rise: A new export for China.

Typically, I was wearing my developed-country hat when I wrote the post, and was considering migration from a developing  to a developed country. While migrant flow is typically in that direction, I missed the important implications for adoption of an IQ-focussed policy by a developing country. As Jones indicates, attracting slightly below average-IQ immigrants from China could boost the mean IQ of many developing states, and following his argument on IQ and trust, improve the country’s institutions and economic outcomes.

Many countries have historically benefited from Chinese immigrants (developed and developing alike), but I doubt if there is any other policy proscription that could deliver greater benefit. As Jones points out in his research, a two standard deviation increase in a country’s average IQ score would lead to a prediction of a 700 per cent increase in average wages, while for an individual, a two standard deviation increase predicts a 30 per cent increase. There are large positive externalities from high-IQ immigrants.

As an end note (and what triggered me to write this post today), test results for Australian students indicate that Australia’s existing immigration framework, which for many migrants has a strong skilled component, is acting as a reasonably strong, but far from perfect, filter. From The Age:

STUDENTS from non-English-speaking backgrounds do better than their classmates in all areas of literacy and numeracy except reading, according to test results released yesterday.

The results of last year’s national literacy and numeracy tests show that students from homes where a language other than English is spoken have higher average scores in writing, spelling, grammar and punctuation and numeracy than students from exclusively English-speaking homes. However, students with English language backgrounds typically do better in reading.

It seems, however, that Australia is unique in achieving this:

The findings are consistent with international test results released in December, showing Australian students with immigrant backgrounds did better on average than those without an immigrant background. Australia was the only nation in which this was true.