New data shows existing tenants are paying less than new tenants.
An ESRI study, funded by the Residential Tenancies Board, found the average rent for new tenancies was 214 euro, or 16 point 4 per cent, more than existing ones.
The largest gaps were found in the north-west, west and parts of the midlands, with smaller gaps in the east of the country.
The percentage difference between rents paid by sitting tenants and new tenants in Donegal ranges from 17.3% for a 2 bed property to 37.8% for a house with four bedrooms or more.
The ESRI says the findings reflect the rapid rental inflation in new tenancies in more rural and less traditional rental markets in recent quarters, as well as less frequent turnover of properties in many of the areas.
You can read the full report here