关键词: 世界人口, 期望寿命, 演变模式

Abstract: At the start of the 21st century,the global population has reached 6 billions.The growth rate is significantly slower.Many countries completed their demographic transition;their TFRs are below the replacement level.Population health,meanwhile,has been improved remarkably-notable decline in mortality,as well as increase in life expectancy.This paper systematically analyzes the global trend,regional variation,as well as pattern in life expectancy in the past 50 years,using mortality data for 192 countries published by United Nations.The results indicate that life expectancy has been globally increasing for the last half century.More than 50 percent of the world’s population lives in countries or regions in which life expectancy is above 70 years old.The trends of life expectancy are diversified in that higher increase in less developed regions than in more developed regions,and the proportion of their population rose significantly.The largest increase in life expectancy occurred in Asia.While improvement in Africa is smaller than the world level,gaps among African countries or regions are great.

Keywords: World population, Life expectancy, Patterns of development