A new study of inflation by the ESRI has found that high income and low income households have different experiences of inflation, with the cost of housing the main difference.  

The consumer price index measures the rise or fall in prices of a basket of goods to produce a state-wide inflation figure.  

But different types of household experience inflation in different ways.

In particular the difference between the cost of a mortgage and the cost of rent can play a big role, depending on what time period is examined.

The ESRI has found that during the last recession - from 2009 to 2014 - the poorest households experienced a higher rate of inflation than richer households due to the falling costs of mortgage inflation and house prices. 

Instead they were disproportionately affected by the sharp rise in rental inflation, as the bottom 10% tend to be renters not buyers of property.

But the opposite happened during the boom years, when mortgage interest inflation soared by a cumulative 120%, but rents went up by 20%.  

The result was the bottom 10% experienced inflation below the state average, while the richest 10% had higher than average inflation.

A similar pattern was shown when inflation was measured against household expenditure, with the lowest spending decile experiencing lower inflation during the boom years.

But when housing costs are excluded the finding is reversed, with lower spending households experiencing faster inflation than high spending households. 

This pattern would have continued during the great recession years of 2009 to 2014, though the deflationary impact of mortgage interest in this period would have reduced the difference in experience between top and bottom spending deciles. 

Studies in the UK have found that low income households experienced higher annual inflation than high income households.  

From 2009 to 2014, the bottom 20% experienced inflation 1% higher than the top 20%. 

In Ireland, during the same period, the ESRI finds the gap was 0.5%. 

The inflation experience of the UK and Ireland has been very different over the period, with average annual inflation in the UK at 2.5% and Ireland at 1.5%. 

Cumulative inflation from 2003 to 2014 was 19% in Ireland and 34% in the UK.  The main difference was the period of deflation experienced in Ireland in the 2009 to 2014 period, when cumulative inflation was 1%, compared to 18% in the UK.