EF English Proficiency Index

I searched online, I searched on Google Scholar, and I haven't really been able to find a reliable global ranking that tells us, for example, that Britain is the best place to learn English, or Australia is number two, or the Philippines is number three.

Rankings such as the EF English Proficiency Index measure how well people speak English in different countries, but they do not measure the quality of English language schools or tell us where a foreign learner will improve the most.

And as far as I could find, there has not been too much academic research comparing educational outcomes for English students between countries.

Probably because there can be such variance in the level and quality of education within a country.