It seems there are a few different versions of the mentioned "The Cost of Friendship" paper. The article links to a paywalled version from 2012, but two updated

It seems there are a few different versions of the mentioned "The Cost of Friendship" paper. The article links to a paywalled version from 2012, but two updated drafts (April 2013 and April 2014) exist, and are freely available: Draft April 2013: https://businessdev.drupal.ku.edu/sites/businessdev.drupal.ku.edu/files/docs/Gompers%20et%20al.%20The_Cost_of_Friendship_GMX.pdf https://businessdev.drupal.ku.edu/sites/businessdev.drupal.k... Draft April 2014: http://people.hbs.edu/yxuan/gompersmukharlyamovxuancostoffriendship.pdf http://people.hbs.edu/yxuan/gompersmukharlyamovxuancostoffri...