I blogged (in Esperanto) about this in April this year. An article had then just appeared in The Guardian which I drew upon. Grim stuff.
Unesco's focus this year is on Literacy and Health: "For instance, a study conducted in 32 countries shows that women with secondary education are five times more likely to be informed about HIV/AIDS than women who are illiterate. Another example: the rate of infant mortality is higher when the mother can neither read nor write."
Amazingly enough, neither the article in The Guardian, nor the Unesco release even mention mother-tongue medium education (MTME). It's not as if MTME's role is unknown - as the Universal Esperanto Association declares:
It has been shown in many large-scale studies in several countries that if indigenous and minority children have their education mainly using their own languages as the teaching language for the first 6-8 years (with good teaching of the dominant language as a second language, given by bilingual teachers), their general school achievement is better and they learn the dominant language better than if their teaching is through the medium of the dominant language.
So, the research is all there, and indeed, has been there for some time - see "Mother tongue first: Children's right to learn in their own languages". Similarly, UNDP's Human Development Report of 2004 tells us that of the children in sub-Saharan Africa who go to school, only 13% have access to mother-tongue medium education. That percentage for indigenous peoples in India is practically zero.
The 38% of India's adivasis who are literate (including the 14% literate adivasi women), can read only in the main regional language.