Fiscal drag happens when the government's net fiscal position (spending minus taxation) fails to cover the net savings desires of the private economy, also called the private economy's spending gap (earnings minus spending and private investment).
Real fiscal drag takes place when tax thresholds are increased in line with price rises to avoid nominal fiscal drag, but where a growing economy means that earnings rise faster still, so increasing taxes as proportion of earnings.
the progressive income tax system has allowed government revenues to swell due to both nominal and real fiscal drag without either increases in the tax rates or decreases in the thresholds.
That is because the country has experienced considerable economic growth, which some attribute to the low-interest monetary regime of the European Central Bank, resulting in high wage inflation.
Whereas others attribute to the economic and educational policies of the Irish government, in subsidizing education and eliminating taxation of the arts, two historically low-income demographics that would thus respond strongly to an increase in income, resulting in price inflation and thus wage inflation to retain purchasing power parity.