The early Colombian indigenous societies had many practices that we would consider economically ludicrous today, such as:
-Human sacrifice to show status (killing talent for ego);
-Burying wealth with dead owners (destroying assets for ego);
-Treating women as chattel (male primate foolishness carried over into homo sapiens).
These are actually practices common to all "backward" societies, but I'm shocked about how variants of them exist today when people claim that increasing wealth (economic prosperity, GDP per capita, the level of the bottom quartile) is a paramount social goal.
From Egypt to Venezuela, the major problem of the world today isn't technology or scarcity, but governance. I would argue that we have the technological, institutional, and cultural know-how to bring many poor countries to the level of Singapore or South Korea in two generations, but bad leaders hinder their own countries.
Let me focus on 3 low-hanging fruit, easy investments that governments can make:
1) Bolstering K-12 education, basic literacy, numeracy, and computer/tech fluency. I think we can replace hundreds of thousands of bad and mediocre teachers with a few good teachers "broadcasted" with software and made interactive with games. MIT's OpenCourseware project and Khan Academy are the very beginning of a massive revolution...
2) Putting a strong focus on government transparency, anti-corruption laws with teeth (see Singapore), and putting most government services on the internet. Most countries don't have identity cards tied to the internet. Besides doing banking and communicating, what about voting, getting EVERY permit, and complete budget transparency? Sorry, even the US or Singapore don't do this!
3) Empowering women through equal education, preferences, and affirmative action. In the US, women are now better educated, but having kids puts them back. Like Sweden, the US needs a much better maternal (and paternal!) support system. Other "developed" countries, like Japan, have backward, 18th century views toward women.
Generally, the US is the best place in the world for entrepreneurship, STEM (science, tech, engineering, and math)innovation, and higher education. However, for social policies on education, clean government, and empowering women, Singapore, Finland, & Sweden are more interesting.