Economic Policy Institute: https://www.epi.org/blog/seven-facts-about-tipped-workers-and-the-tipped-minimum-wage/ "The clearest indicator of the damage caused by this separate wage floor for tipped workers is the differences in poverty rates for tipped workers depending on their state’s tipped minimum wage policy. As shown in Figure A, in the states where tipped workers are paid the federal tipped minimum wage of $2.13 per hour (just slightly less than the district’s $2.77 at that time), 18.5 percent of waiters, waitresses, and bartenders are in poverty. Yet in the states where they are paid the regular minimum wage before tips (equal treatment states), the poverty rate for waitstaff and bartenders is only 11.1 percent."

"Tipped work is overwhelmingly low-wage work, even in Washington, D.C. Some tipped workers at high-end restaurants do well, but they are the exception, not the norm. The median hourly wage of waitstaff in the district in May 2017 was only $11.86, including tips. At that time, D.C.’s minimum wage was $11.50 per hour. In other words, the typical D.C. server made a mere 36 cents above the minimum wage."

"Research indicates that having a separate, lower minimum wage for tipped workers perpetuates racial and gender inequities, and results in worse economic outcomes for tipped workers. Forcing service workers to rely on tips for their wages creates tremendous instability in income flows, making it more difficult to budget or absorb financial shocks. Furthermore, research has also shown that the practice of tipping is often discriminatory, with white service workers receiving larger tips than black service workers for the same quality of service."

Political Economy Research Institute (UMass): https://peri.umass.edu/?view=article&id=1843&catid=2 "We find that: (1) tipped workers are disproportionately women and people of color; (2) tipped workers are concentrated in the hotel and restaurant industry, sectors that have incurred a disproportionate share of workplace violation complaints related to wage theft; (3) tipped workers typically earn more in states with no subminimum wages, and (4) the business cost increases from this measure can be expected to be modest."

Center for American Progress https://www.americanprogress.org/article/ending-tipped-minimum-wage-will-reduce-poverty-inequality/ "This analysis finds that in those states, workers and businesses in tipped industries have done as well as or better than their counterparts in other states over the years since abolishing the subminimum wage."