Consumer confidence has weakened in the past month due to higher energy costs and rising interest rates, according to the ESRI and IIB Bank.
In their latest monthly assessment, the two organisations say their consumer sentiment index fell from 90.9 in July to 84.8 in August.
The figure represents the third monthly decrease over the past four months.
The ESRI and IIB Bank say half of all those questioned as part of the research expected the economic situation to worsen in the next 12 months.