Via Voxeu , I discovered a study in India interested in the relationship between control English and average salary:
This chart shows that on average, those who speak English have higher wages. The question that arises is whether this correlation is causation or not. Is that to speak English increases the salary or is it that people who have a good job are also those who on average are more educated and speak better English?
According to the authors, it is. They believe that knowing perfectly speak English to an Indian reservation wage increases the third. Moreover, this premium is even larger than the individual has a high degree. After reading the study, I think those estimates are a bit overpriced but the performance of learning English is not insignificant.
As for negative points, the authors observe the impression of "diminishing returns": the more workers who speak English, it becomes less interesting to learn English. They show that English proficiency is profitable for all workers "adults" but that most young people can gain an advantage if they have a high level of education.
Are these results are transferable to industrialized countries? The authors do not say, but I think it's more than likely, though the extra pay is probably lower compared to India.
