The Nevin Economic Research Institute has said the case for cutting taxes in the next Budget is very weak.
The organisation said any extra money available to the Government would be better spent on infrastructure, education, research and childcare.
The economy will grow, the Institute said, by just over 4% this year, a little less next year.
Employment will also continue to increase, with the unemployment rate falling below 7% by the end of 2018.
However it believes Brexit is likely to impact negatively over the medium term.
In that context, the Institute said budget policy should focus very meagre extra resources on boosting the productive capacity of the economy and employment.
It recommended, therefore, using available fiscal space on infrastructure, education, research and development and childcare, instead of on tax cuts.
Tax reforms to smooth out jumps in the tax system can still be undertaken, the Institute said, but it added that Ireland is not a high tax economy, and the case for tax reductions therefore is a weak one.