I am advised by the Revenue Commissioners that the total identifiable costs to the Exchequer currently available relate to Income Tax and Corporation Tax allowances, reliefs, exemptions and tax credits for 2012 (the latest year for which figures are available). These cost estimates are published in the Costs of Credits, Allowances and Reliefs tables on the Revenue Statistics web page available at http://www.revenue.ie/en/about/statistics/index.html#section4. Updates will be published in due course.
There are other expenditures, not included in the above, for which estimates of costs are not readily available. For a fuller listing, I refer the Deputy to my answer to Question No. 195 (36716/14) on 30 September 2014.