Interesting, but I wish the author had considered attrition rates rather than just employment. A US citizen is free to leave a graduate program without jeopard

Interesting, but I wish the author had considered attrition rates rather than just employment. A US citizen is free to leave a graduate program without jeopardizing residency rights (and is also free to pursue career paths that are less likely to have visa sponsorship). As a result, unsuccessful American PhD students may be less likely to muddle through and complete a degree (but be difficult to place). I could see this affecting numbers where it comes to placement after the PhD is obtained.