How do we improve a country's (or region, community) education level?
From the research perspective, the first question to ask is 'what do we mean by education level?' Normally we use school enrollment rate to see how much is the share of population of a specific school age are enrolled in schools. Alternatively, we can use average test scores for quality measurement. There are many other measurements, depends on what do we want to see, but those two are the most common.
The next question is on what policy (intervention) to take. Is 'increase education budget' is the answer? Well, money is always nice, for sure. But what will the money for? To build more schools, to pay teachers, to provide scholarships? If someone do the counts of what appear in newspapers, these things are probably mentioned the most. The problem is, these interventions assume that the problems with education lies on the supply side, and budget is the biggest constraints.
However, this may not necessarily be so. Maybe school enrollment is low because, well, people don't see the point of going to school. Maybe test scores are low because students don't come to school for any reasons. Or, they do come to school but not for studying (i.e. beating their fellow students, like these guys).
Or, they do come to school but can not understand what the teacher says because of some other reasons. One possible reason is: incestinal worms. This is what Eduard Miguel and Michael Kremer found in Kenya. Worms infected billions of children around the world, and the problem is the most serious in Africa. When you are infected with worms, you share your nutrition with them, affecting your ability to grasp materials. Or worse, periodically you would have to be absent from school because of certain disease caused by worms. According to Miguel and Kremer, deworming program proves to be effective in increasing school attendance rate and raising test scores with lower cost than other types of intervention (like subsidizing school uniforms).
That was in Kenya. There is a similarly interesting story from Kepanjen Subdistrict, Malang, East Java. A local doctor found that attendance rate was not a problem there, but performance was. Later he found that, among other things, performance of students was affected by... earwax. Well, you know the channel. No rigorous studies have been done, but headmasters reported that regular de-waxing program increased average test scores.
Apparently, small things can lead to big changes.