The Deputy also may be interested in the Post-Budget 2016 Ready Reckoner available on the Revenue Statistics webpage at http://www.revenue.ie/en/about/statistics/index.html. This Ready Reckoner shows a wide range of detailed information, including the estimated cost to the Exchequer when various tax bands including Single, Married One Earner and Married Two Earner are increased.
In relation to the element of the Deputy's question regarding an increase in the standard rate band for a one-parent family, it has been assumed for the purposes of this reply that the Deputy is referring to individuals who qualify for the Single Person Child Carer Credit (SPCCC), a tax credit available to a single person who is the primary carer of one or more children. A person who qualifies for the SPCCC is also entitled to an €4,000 extension in the standard rate band, which increases the rate band from €33,800 to €37,800. The estimated first and full year cost to the Exchequer of increasing this specific band to €45,000 is in the order of €19.6 million and €26.6 million respectively.
The Deputy may wish to note that a standard rate band system such as that outlined, allowing a €36,000 rate band for single individuals and €70,000 for a married couple or civil partners, would give rise to Constitutional issues. There is a Constitutional requirement, deriving from the Supreme Court decision in Murphy v. the Attorney General (1980), that a married couple must not have a greater tax liability than two single people living together and having the same income. For this reason the current maximum married two-earner band of €67,600 is double the value of the single band of €33,800.
All figures provided in the Ready Reckoner are estimates for 2016 incomes from the Revenue tax forecasting model using latest actual data for the year 2013, adjusted as necessary for income, self-employment and employment trends in the interim. They are provisional and may be revised.