HDI

When they calculate the data they use statistics for international data agencies. As I began to click on countries, to name a few, the Philippians, Italy and the United States, they seemed similar in life expectancy. But I think that they are similar because the United States for example is more developed (financially, with technology,etc.) then other countries and regions.
The Human Development of the world, varies according to the region, for example North America has high human development but Africa has low human development. I think that part of that has to do with that fact that there is the Sahara Desert that is in a big part of Africa. That would explain a lot when it comes to numbers in Human Development, the environment and land can not support the people.