There are four reason why emerging-market economies are growing faster than developed-market economies:
Demography: The population of the developed economies is older than emerging markets except for China and Russia. The average American is 38 years old. The average Brazilian, 31. The average Indian, 27 and the average African, only 19. A younger population equals a growing pool of workers to produce goods and services as well as a growing pool of consumers to buy them.
Urbanization: Bulk of the population in emerging markets still lives in rural villages. 52% to be exact. As people move to urban areas, or as villages are converted into towns and cities, people have access to better amenities. All of these developments fuel economic growth.
Infrastructure: Developed economies already have developed infrastructures. In contrast, with the exception of China, almost every emerging market in the world is short of infrastructure. As these economies invest into infrastructure, their economies benefits.
Productivity: Developed economies have already maximized ways to make each hour of each person more productive. In contrast, emerging markets are likely to enjoy higher growth rates in labor productivity for at least the next 20 years.