Promoting self-esteem
The theory is that if everyone has high self-esteem, then everyone will be successful and live a happy life. If a society was inoculated with high self-esteem, it would end poverty, crime, and violence.
But, one should take into account that high self-esteem could be the result of success, not necessarily the cause. Also, thinking that only one thing can explain how to be successful, is probably naive.