Oprah Winfrey’s struggling television network, OWN, said Monday it is laying off one-fifth of its workers and restructuring its operations in New York and Los Angeles. The decision to let 30 employees go is a “tough” one, but the economics of a start-up cable network didn’t fit with OWN’s cost structure, Winfrey said in a statement. “As CEO, I have a responsibility to chart the course for long-term success for the network. To wholly achieve that long-term success, this was a necessary next step,” Winfrey said.