CNNMoney: Facebook Inc. announced plans Wednesday to require its U.S. contractors and vendors to pay their employees at least $15 an hour and offer paid time off for sick days and vacation. Facebook will also require contractors to offer a $4,000 “child benefit” for workers who don’t already get parental leave. “Taking these steps is the right thing to do for our business and our community,” said Sheryl Sandberg, Facebook’s chief operating officer and an outspoken advocate for women in the workforce. Sandberg said the changes are particularly important for women, since they make up the bulk of minimum-wage workers nationwide. She said in a blog post that providing benefits contributes to “a happier and ultimately more productive workforce.”