In preparing Exchequer tax forecasts the methodology adopted by my Department at Budget time involves the estimation of the outturn for the outgoing year across a series of tax headings. This becomes the base for the preparation of the projection for the forecast year. The resulting projected outturn is then adjusted as necessary to take account of the effects of previous Budget measures which may have a pass-through effect or any known one-off factors likely to impact upon the yield. To this resulting "cleaned" base, the key macroeconomic driver of each tax heading, is applied. The impact of any Budget day policy measures are also incorporated. With respect to macroeconomic developments, I would draw the Deputy's attention to the fact that it is the nominal growth rate of GDP (i.e. volume and price changes) which drives overall tax revenue and affects the various fiscal ratios.
As we are only a month into the New Year, it is too soon to be talking about the impact of on-going influences on the Exchequer tax receipts for this year. My Department will continue to monitor the economic and budgetary situation over the coming months, in particular the monthly Exchequer Statement, and this will inform official thinking on these matters. As is the norm, my Department will publish a revised set of economic and budgetary forecasts in the April Stability Programme Update.