Trends in life expectancy in Europe: one big explanation or many small ones?

Excerpt

In seeking to understand different types of knowledge, the philosopher Isaiah Berlin invoked the Greek fable of the hedgehog and the fox [1]. The hedgehog knew one big thing but the fox knew many little things. He was seeking to differentiate the quest for grand unifying theories that would explain a phenomenon in its totality from that seeking many different explanations, each explaining a particular aspect of it. Academics are faced with powerful incentives to pursue the former, developing theories in one setting that can explain what happens in another and which, if they succeed, will guarantee them immortality (or at least publication in a leading journal and a stream of citations that will last until a better theory comes along). Policy-makers, on the other hand, often struggle with such theories, noting how the day to day reality they are experiencing rarely behaves according to the theory being proposed. …