Edward Marks on Understanding Life Expectancy

Edward Marks has a fantastic article on how you should think about life expectancy numbers.

If you type “life expectancy” into Google, it will spit back the World Bank estimate of 78.2 years in 2010. You’ve likely read numbers close to these in textbooks and articles.

But what do these numbers actually mean? You might guess from the first that someone born in the United States in 2009 could be expected to live about 78.5 years. This is not the case! It actually measures how long someone would be expected to live if every year of their life was spent in 2009.

Be sure to check out the full post, it's a great read.