An old Chinese saying (I assume all Chinese sayings are old except the ones that come from the little Red Book) goes:
If you are planning for a year, sow rice; if you are planning for a decade, plant trees; if you are planning for a lifetime, educate people.
In the context of development, I think the last bit should be “if you are planning for a nation, educate people.” Especially, primary education. For among all the factors that are necessary for economic development, …