This is a statement from a recent Business Insider’s article, which shows the results of two research papers studying the TIMMS test and the Programme for International Student Assessment, or PISA, in an attempt to understand the "Vietnam effect.”
Accordingly, investments in education and "cultural differences" in Vietnam can explain about half of the point difference. In general, Vietnamese students were more focused and took their schoolwork more seriously. They were less likely to be late for school, had fewer unexcused absences, and skipped fewer classes. There’s a higher emphasis on student achievement than in other developing nations. But, importantly, Vietnam seems to invest in education more than other developing countries, especially considering its lower GDP. However, researchers also said these factors together only account for half of the achievement gap. The rest of the Vietnam phenomenon remains a mystery.