13b gap between tax & spending includes NI share of spending that will stay in GB, nuclear weapons, debt, pro-rata share of pensions etc. €3b is the year one gap between tax & spending that would stay in NI plus a boost of €1b

The costs associated with Unity have tended to be exaggerated and the benefits of an all-Ireland economy largely ignored. Without underestimating the difficulties, the aim of this report is to contribute to the discussion by demonstrating the range of possible costs and benefits

However, it is unlikely that the necessary policy change could be secured within the UK in the short-to-medium term political context. Some issues such as full access to EU services market

Some of the necessary policy changes to boost productivity and wages could be delivered in a stronger model of devolution to NI inside the UK, such as higher spending on education, infrastructure and on R&D, a competitive corporation tax policy, a more equitable tax policy.

In the worst case scenario where the UK refuses to any pensions whatsoever - even to retired public sector workers - the fiscal transition would still reach break even between 8 and 14 years.

The ‘deficit’ of just over €3b pa would be a ‘subvention’ from the ‘South’ funded by taxes or borrowing of less than three quarters of one per cent of GNI* in year one, (falling gradually as the economy grows) and reaching breakeven point within 5 to 9 years.

With NI achieving a growth rate of 2% above recent historic norms after unity (mid-level of Central European performance), the fiscal deficit would end by year 6, by year 10 NI would have an annual surplus of €3.6b pa , or more likely fund further improvements to public services

GDP convergence would happen but slowly, but public finances would improve more quickly. Report looks at 3 scenarios - reflecting the experience of Central Europe after they joined the EU, and at the mid range reflecting the South's performance.

Model based on an assumption that with the same set of policies on education, infrastructure, tax and Foreign Direct Investment, there is no reason why Northern Ireland would remain so much poorer and so much less economically productive than other parts of the island.

NI economy grew (real terms) by just over 30%, between 2000 and 2024, average of 1.3% pa. Using modified Gross National Income GNI* to exclude the distortions from multinational operations, the Republic’s economy grew by 71% over the same period, an average of just over 3.2% pa.

Model in the report increases public exp by one billion euros pa - maintained for the ten years - to deal with health, education, infrastructure. Public sector wages increased by 48% to bring in line with South over 15 years (as an example). Starting deficit is therefore €3b

At present the full cost of UK central state agencies is allocated to each region based on population, but tax paid by employees (and VAT) is credited to the region when that central office is based (mostly London). This increases the subvention artificially.