From the summary:
The recession and resulting public deficits have put a spotlight on public sector pay and compensation levels. Many governments have enacted pay freezes, pay constraints and are proceeding with contracting out of public services, partly on the perception that public sector workers are consistently paid more than those working in comparative jobs in the private sector.
This study uses the most detailed comprehensive data available on earnings by occupation and finds the reality is quite different. Overall average pay in the public sector is very similar to pay for comparable occupations in the private sector. Public sector pay is also considerably more equitable, whether measured by gender, age, occupational group or by region.