DOI link for World Population
World Population book
World population growth is dependent on many factors, but the primary ones are the demographic transition status of the individual societies and the fertility rate. Inexpensive oil and high agricultural productivity go hand in hand and encourage population growth. They improve economic conditions so young people are more likely to start families or increase families, knowing that they will be able to support them. Immigration policies and local economic factors affect movements of peoples in evaluating demographic changes. Education and poverty are important metrics for program and portfolio planning managers. Birth rates in first-and third-world countries, Organisation for Economic Co-operation and Development (OECD)  and non-OECD countries, are determining the shape and location of the workforce, and both are changing, but at different rates. Migration and immigration policies determine population demographics.