I'm reminded of an Order of the Stick comic where V asks two shopkeepers how they manage to stay in business when they sell their potions for 2gp when the resources cost 3gp wholesale. They respond "How do we do it? VOLUME!" and launch into a long-winded explanation about how recouping profits from reduced prices by selling lots of things works? while V is screaming at them because they're effing stupid.
That said: four week, longer day, year round, possibly block scheduling (the data is mixed here) would probably get good results IF we drop these ridiculous standardized tests. And are not afraid to let elementary kids learn something, and maybe even fail grades if they don't deserve it. Maybe guarantee that a teacher won't have to teach a kid two years in a row unless they are the only one who can teach their class. Pay teachers more, teach them better, and make the hiring minimums more stringent. Don't accept teachers who teach poorly - and use a metric that is not the percentage of their damn class that they pass. Acknowledge that kids have different strengths, academically and otherwise, and use that to the advantage: whether that's tracking, or mixed-grouping, or whatever.
And somehow parents have to get involved. That's a much more complex problem to solve, especially since we live in a world where many of the parents grew up in a system that oppressed them too hard - now instead of being on the teachers' side like they almost always have been before, they stand by their kid when (s)he does something stupid.
Of course, this is all way too controversial, because how will the kids feel? Failing a class? Horrors, can you imagine the psychological damage? Everyone seems to forget that the kids have an agenda too, and if you totally ignore it they will rebel and if you actively try to cater to it too closely they'll change it to be favorable to their short-term wants. So why aren't their short term wants to learn? The truth is, learning, low-cost failure, and problem solving are fun. That's why video games work. That's why TV shows like Lost work. That's why sports work. But education doesn't seem to work. It's the trappings of freedom without the benefits, it's the incongurity between what adults say and what they do, it's the fact that nobody ever seems to care about what they have to say; that's why kids really don't invest in their education.
My 2¢. Okay, maybe more like 3¢.