NLRB general counsel Richard Griffin Jr. wrote in a letter on Tuesday that 43 of 181 worker complaints filed against McDonald's have merit and that the fast food chain would be named as a joint employer.
That means McDonald's could be liable for unfair labor practices, like low pay, at the franchise locations.
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Franchises are purchased by an individual or group to sell a company's goods within a certain area or location.
"The NLRB letter means that not only is the franchise owner responsible for making sure there's fair working conditions, but also a firm like McDonald's is responsible," said Kathy Ruckelshaus, general counsel for the National Employment Law Project, a pro-workers organization.
She added, however, that it's too soon to tell whether the ruling will prove a boon to organized labor.
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"They weren't seeking a union, but trying to make their jobs better when it comes to pay," Ruckelshaus said. "We have to wait to see how this plays out."