“…changes in educational structures can have dynamic effects on entire economies. A list of the richest countries in the world is dominated by open, trade-driven economies. Oil economies aside, the top 10 includes countries where trilingualism is typical, like Luxembourg, Switzerland and Singapore, and small countries like the Scandinavian ones, where English knowledge is excellent.
There are of course many reasons that such countries are rich. But a willingness to learn about export markets, and their languages, is a plausible candidate. One study, led byJames Foreman-Peck of Cardiff Business School, has estimated that lack of foreign-language proficiency in Britain costs the economy £48 billion ($80 billion), or 3.5% of GDP, each year. Even if that number is high, the cost of assuming that foreign customers will learn your language, and never bothering to learn theirs, is certainly a lot greater than zero. So if Mr Saiz had run his language-premium study against a parallel-universe America, in which the last half-century had been a golden age of language-learning, he might have found a bigger foreign-language bonus (and a bigger GDP pie to divide) in that more open and export-oriented fantasy America. And of course greater investment in foreign-language teaching would have other dynamic effects: more and better teachers and materials, plus a cultural premium on multilingualism, means more people will actually master a language, rather than wasting several years never getting past la plume de ma tante, as happens in Britain and America.”
Source: Language study: Johnson: What is a foreign language worth? | The Economist.