Actually,it depends on one country's population are how much educated,sincere,honest and responsible to their country.
No matter how many people are educated, sincere, honest or responsible, there is not way that that country will be rich if the government are not responsible to his duty and his country. A dedicated leader do not look at what the people say to his works but he is focused in the results that it will bring in the future. You don't even need a nation that is sincere and honest, you just need an educated, smart and skillful people.
Also depends on this country's government,political issues,development system,managements etc.
Maximizing these things, it all comes to the government. So it just really depends on that Country's Government.