Failure to contribute
Bruckner, Caroline, and Thomas L. Hungerford. “Failure to contribute: an estimate of the consequences of non- and underpayment of self-employment taxes by independent contractors and on-demand workers on Social Security”. CRR WP 2019-1, Chestnut Hill, Mass.: Center for Retirement Research at Boston College, January 2019. http://hdl.handle.net/2345/bc-ir:108277.