1950 and 2010, 35 of 52 middle-income countries became trapped.8 If we look at the World Bank’s 167 member countries in 2016 (excluding the 48 oil-producing countries and low-population, high-income island states), there were 31 low-income nations (less than $1,045 of income per head), 51 lower-middle-income countries ($1,046 to $4,125), 53 upper-middle-income countries ($4,126 to $12,735), and 32 high income countries, which were all members of the OECD.
