What is wrong with that sentence?
Historically, the cosmetology industry, which includes barbers and hair stylists, have been classified as independent contractors...
**What is wrong with that sentence?**
First this: “the cosmetology industry, which includes barbers and hair stylists, have been...”
Industry is singular, have been in plural. It should be “industry has been”.
Next, either grammatically correct or not it makes no sense.
...the cosmetology industry [...] have (sic) been classified as independent contractors.”
Industries cannot be independent contractors. Human brings who work in certain industries can be independent contractors,