One of the basic necessities for human welfare is, of course, life itself. Life expectancy is therefore an essential aspect of any welfare measure. However, living longer does not necessarily mean living better, if that extra time is simply spent suffering more. It is therefore also important to consider whether we live healthier lives and spend less time being ill.

The main point of this chapter is to show how our lives and our health have improved dramatically over the past couple of hundred years. We live longer, and we are more healthy. This is one of the great miracles of our civilization.

Life expectancy

Until around the year 1400, human life expectancy was amazingly short – a newborn child could on average only expect to live 20–30 years. This was mainly due to the fact that infant mortality was incredibly high. Only every other child survived beyond its fifth birthday.

For the early part of human history we have little or no precise statistics to rely on, so the figures must be based on the examination of skeletons and on mathematical population growth models.