Some low-paid workers suffered a drop in their working hours after the minimum wage increased early last year.
A new study from the ESRI shows those in hospitality and retail living primarily in Dublin and the west lost roughly one and a half hours a week in the first half of 2018.
Manufacturing workers also lost the same amount of time over the period.
In January 2018, the minimum wage increased from €9.25 per hour to €9.55 per hour.
However, the ERSI found that changes to hours did not continue into the second half of 2018, "suggesting that any impacts were likely to have been temporary."
Professor Seamus McGuinness, an author of the report, said: "It is important to recognise that minimum wage changes can affect particular areas of the labour market differently and studies focusing only on national data risk missing important impacts.
"While in this instance we found that any regional and sectoral changes were short-lived, it is important that we continue to monitor this, as impacts could become more persistent during periods of lower economic growth."
