That is far above the 10% reported by INDEC, the government statistics agency, but less than the 30% wage increases public employees have received in recent years.
Much of recent job growth has been in lower-wage industries, notes Martin Kohli, chief regional economist with the Bureau of Labor Statistics in New York City.
Evidence from the American Bureau of Labour Statistics support the conservative argument that they have used their power to extract a wage premium: public-sector workers earn, on average, a third more than their private-sector counterparts.
The statistics do not reflect the impact of more recent policies such as the national minimum wage and the working families tax credit, however and the reseachers say it is too early to judge Labour's overall strategy.