Why so few female economics bloggers?

An issue raised by male blogger Matthew Kahn,

REPEC provides an objective measure of who is "Royalty" in the economics profession. The current list of the top 5% is here. I am ranked #681 out of 27,365 economists so that's not bad (and my 3 books aren't counted here). But, here is the interesting part. There are 39 women who rank in the top 1000 and 0 of them blog. Contrast that with the men. Consider the top 100 men. In this elite subset; at least 8 of them blog. Consider the men ranked between 101 and 200. At least, six of them blog. So, this isn't very scientific but we see a 7% participation rate for excellent male economists and a 0% participation rate for excellent women. This differential looks statistically significant to me.

The answer could be very simple. Its possible that female economists simply have a higher opportunity cost of time and the returns to blogging are low.