It is literally one of the criteria that the IRS uses to decide whether someone is an employee or an independent contractor. From https://www.irs.gov/businesse

It is literally one of the criteria that the IRS uses to decide whether someone is an employee or an independent contractor. From https://www.irs.gov/businesses/small-businesses-self-employed/independent-contractor-self-employed-or-employee#SE https://www.irs.gov/businesses/small-businesses-self-employe... : "In determining whether the person providing service is an employee or an independent contractor, all information that provides evidence of the degree of control and independence must be considered." One of the categories of control and independence is behavioral, which is described here: https://www.irs.gov/businesses/small-businesses-self-employed/behavioral-control https://www.irs.gov/businesses/small-businesses-self-employe... It says: "An employee is generally subject to the business’s instructions about when, where, and how to work." Uber, Lyft, etc. leave the driver to decide which car they drive, where they buy gas, which jobs they take, and when they work or don't work. This is a big part of what goes into justifying their legal status as contractors rather than employees.