The modest homes see the biggest increase in prices, whereby buyers with money are more likely to get cheaper real estate than the ones they prefer.
This is mainly due to the fact that cash customers are more active in the lower end of the housing market, pushing the prices of smaller homes in less desirable areas.
This means there is a limit on the ability of central banks to lend rules for real estate pricing, the study economist has found.
Cash buyers can represent up to half of all purchases of residential real estate.
These customers include corporations and non-governmental agencies. They also include households using equity from their home, or bank deposit, to finance buy-to-let purchase.
The mortgage finances six out of 10 purchases in Dublin, but only four out of 10 purchases are funded by mortgages in other parts of the country.
Central Bank economist Edward Gaffney's findings show that modest homes were mostly bought by cash-in-cash customers.
Competitiveness among cash customers for lower property values is pushing prices at much faster rates than for expensive real estate financing the mortgage.
Between 2016 and 2018, the prices of modest properties increased by 15 percent.
At the upper end of the real estate market prices have risen by 6pc.
"Banks usually borrow to finance real estate purchases at higher prices, while non-mortgage financing is dominant at lower prices," said Gaffney.
Lending limits, which is formally referred to as macroprudential mortgage measures, means that first customers need a 10-second deposit.
Other buyers who receive a mortgage need to pay or capital, 20% of the value of the property they buy. There are some exceptions.
Customers can also borrow more than three and a half times their income, although there are some exemptions.
Commentators have put in credit limits by keeping the real estate price growth rate on a single digit, measured by the Central Bureau of Statistics.
The Economist of the Central Bank, Mr Gaffney, found that lending limits have less impact on the modest prices of houses where cash prevalent customers are concerned.
However, lending restrictions work to keep prices on the higher end of the real estate market where people have to use mortgages to have a home.
This means that there is a "structural restriction" on the influence of the Central Bank macroprudential rules on real estate prices.