More about Andrew: http://www.aei.org/scholar/andrew-g-biggs/
The Paul Samuelson article I refer to: https://www.washingtonpost.com/opinions/dont-expand-social-security-our-elderly-are-mostly-fine/2019/02/10/a65ae6ce-2bc9-11e9-b011-d8500644dc98_story.html