The finding came as controversy broke out among senior politicians over whether the government should lift the cap on public sector pay increases.
This was further stoked by 17 health sector trade unions making a call to ministers to drop their policy that PRBs should recommend pay rises costing only an average of 1%, the maximum the government would fully fund.
Work by researchers from University College London found there was a decline of 5.8% in median real gross hourly occupational earnings between 2005-15, which was 3.1% among those covered by a PRB and 6.1% for those outside this mechanism.
Nurses and nursing auxiliaries covered by a PRB earned more than their counterparts elsewhere but radiographers experienced significantly lower earnings growth than those not in a PRB.
“The degree to which earnings growth varies across occupations even within the PRB sector, and after accounting for workforce changes, is, perhaps, the biggest finding from the study,” the report said.
“This is despite a fairly uniform public sector pay policy being applied to these groups over the latter half of the period.”
Teachers covered by a PRB experienced a slightly smaller real earnings decline than colleagues outside this mechanism and police and prison officers experienced moderate earnings decline.
Shadow chancellor John McDonnell said: “This a damning report that reveals the harsh and unfair reality of the Tories’ pay freeze on hard working public sector workers.
“The fact that some of the pillars of our community and the public sector such as teachers, doctors and police officers are seeing their pay cut exposes the double standards of a government that likes to praise their work but will not actually truly reward it.”
The Office of Manpower Economics is a non-departmental public body that provides an independent secretariat to eight PRBs, which cover some 2.5m employees in all.
