“Studies from sick-leave advocacy groups — including the Institute for Women’s Policy Research , the Urban Institute and the Drum Major Institute for Public Policy — conclude that businesses have emerged largely unscathed.

“Most San Francisco employers reported that implementing (the ordinance) was not difficult and that it did not negatively affect their profitability,” said a report from the Washington-based Institute for Women’s Policy Research. The study was based on a 2009 survey of 727 employers and 1,194 employees in San Francisco.

“Two-thirds of all employers are supportive of the law,” said the report’s co-author, Robert Drago.”