There are a number of things that could be done to improve academic achievement in schools. Of course, they typically tend to be much easier to propose than to actually implement. In other words, it is not clear that either of my two proposals could actually be put into practice.
The first thing that I would do is to have more demanding classes. At least at schools where I have taught, classes tend not to force students to really push themselves. I believe that students who are not asked to push themselves will not do so on their own. Therefore, I would propose creating classes that are more challenging.
The second thing I would do is something that is very controversial. I would create classes of different levels of difficulty. In essence, I would do “tracking.” I think that it would be better to have lower-achieving students in a class together. I could then create a curriculum that would challenge them. At the same time, I would have the more advanced students doing work that would be challenging to them but which would be completely over the heads of the students who are not as advanced. This way, more students would be challenged to do work that was difficult for them.