In much of the world today, the incomes of the poor are growing. The World Bank calls this concept shared prosperity, defined as the average annual growth in income or consumption of the poorest 40 percent (the bottom 40) within each country. So, if shared prosperity in a country is positive, the poor are getting richer.
In addition, the shared prosperity premium is defined as the difference between the annual income or consumption growth rate of the bottom 40 and the annual growth rate of the mean in the economy. A positive premium indicates that the bottom 40 are getting a larger share of overall income in the economy.