​​Over 100 countries are in a 'middle-income trap'. What is it and how can they escape?

6 billion people live in middle-income countries today. Where per capita income is between $1,136 and $13,845. Many of these nations are targeting high-income status within the next few decades. But since the 1990s, only 34 have been successful including Saudi Arabia, Latvia, Bulgaria and South Korea. The remaining 108 countries are caught in what the World Bank calls the ‘middle-income trap’.