Part of it may be social networks. Recruiting "everyone" usually ends up being recruit "everyone you know". And social circles are often not terribly diverse: h

Part of it may be social networks. Recruiting "everyone" usually ends up being recruit "everyone you know". And social circles are often not terribly diverse: http://www.washingtonpost.com/blogs/wonkblog/wp/2014/08/25/three-quarters-of-whites-dont-have-any-non-white-friends http://www.washingtonpost.com/blogs/wonkblog/wp/2014/08/25/t...