Public sector pay and pensions will cost €19.5 billion in 2018, according to the latest research from the Institute of Public Administration.
In 'Public Sector Trends 2018', Dr Richard Boyle found that the number of staff employed in the public service - 323,000 - now exceeds the peak figure in 2008 before the economic crash.
Dr Boyle says that citizen's view of of the provision of public services in Ireland has improved, with 60% of the public, and just under half of business users, seeing the civil service as efficient.
On this measure, Ireland now ranks just above the European average.
However, trust in the gardaí has fallen significantly.
Dr Boyle said that the fall in trust in the gardaí was notable, given that trust in other areas of public administration was holding firm or improving.
He noted that satisfaction with the quality of healthcare is below the European average - but by contrast, satisfaction with the education system is among the highest in Europe.
Dr Boyle found that Ireland ranks first in Europe with regard to open data maturity - up from 18th in 2015.
His research also established that the number of women in senior public service management positions is low in comparison to other European countries.