From 2016. This paper did not get the attention I believe it deserved:

How higher labor standards affect how firms behave on the ground. This type of work is extremely valuable—indeed, essential to place statistical patterns in proper context—is difficult to do, and so needs to be highlighted more:

T. William Lester: Inside Monopsony: Employer Responses to Higher Labor Standards in the Full-Service Restaurant Industry: "Employer responses to higher labor standards through a qualitative case comparison of the full service restaurant industry.... San Francisco—where employers face the nation’s highest minimum wage, no tip credits, a pay-or-play health care mandate, and paid sick leave requirements—and... North Carolina’s Research Triangle region—where there are no locally-enacted labor standards.... Higher labor standards led to wage compression in San Francisco even while some employers continued to offer greater benefits to reduce turnover. Employers in San Francisco exhibit greater investment in finding better matches and tend to seek higher-skilled, more professional workers, rather than invest in formal in-house training. Finally, higher wage mandates in San Francisco have exacerbated the wage gap between front-of-house and back-of-house occupations—which correlate strongly with existing racial and ethnic divisions. Initial evidence shows that some employers have responded by radically restructuring industry compensation practices by adding service charges and in some cases eliminating tipping...