The reasons for this growth pattern is that in poor societies population grows by big numbers. This is because poor societies lack literacy and employment. They are of the view that a big family will be helpful in supporting their family as each one of them will earn when they grow big. Whereas wealthy or developed societies favor a small family so that they can be properly educated and brought up. That is the main reason why the poor societies will grow by 1.7 Billion people. This growth would create an extreme imbalance in the world. As the number of poor would increase drastically. The rich will be few and privileged. The crime rates would increase as the poors will be frustrated. The literacy rate of the world would also be low. The donations from the developed nations would increase but even then they would not be able to cover the entire world.
About The United Nations. What Are The Possible Reasons For This Growth Pattern? What Are The Consequences Of This Growth Pattern?
There is a basic culture and demographic (fancy word for saying the economic study of a region or a lifestyle according to income) trend in society that the wealthy reproduce less than the poor.