Where are all the women in economics?

We hear a lot about the under-representation of women in so-called STEM fields - science, technology, engineering and maths. But the proportion of women in economics is by some measures smaller. In the US, only about 13% of women hold permanent academic positions in economics; and in the UK the proportion is only slightly better at 15.5%. Only one woman has ever won the Nobel Prize in economics - American Elinor Ostrom in 2009. And there wasn't even a single woman on some of the lists floating about guessing who this year's prize winner would be - it went to the behavioural economist Richard Thaler.