The age pyramids of peripheral countries or underdeveloped countries have characteristics related to the poverty of such populations, with wider base and narrow apex. The base age range if much wider than the other levels showing high birth rate. The levels just above the base may present impressive reduction in poorer populations due to infant mortality. Ranges that represent the youth are also wide showing future pressure on job and habitation needs. The widths of the rectangles diminish as age increases to the apex that represents the elderly, demonstrating difficult life conditions, precarious health services, and low life expectancy.