What determines gender political quotas?

According to this article by Gay, Santacreu-Vasut, & Shoham the main determinant is female/male distinction in language:

The abstract:

This article studies the determinants of gender political quota and enforcement sanctions, two key policy instruments for increasing female participation in politics. We find a novel empirical fact: language (the pervasiveness of gender distinctions in grammar) is the most significant related variable to quota adoption, more than traditional explanations such as economic development, political system and religion.

A draft is here.