In their conclusions, the authors recommend Northern Ireland – which remains relatively poor and heavily reliant on public sector spending and employment – embark on major reforms to improve its residents’ standard of living.
“Even though Ireland has a much higher national income, funding the needs of the people of Northern Ireland in a united Ireland would put huge financial pressure on the people of Ireland, resulting in an immediate major reduction in their living standards,” the report says.
The whole article(and/or the study) does not mention the cost of the current split(border,trade barriers-especially after Brexit, etc.) and how that affects both Irelands daily. And it neither talks about the EU funding Ireland would get for dealing with Northern Ireland - which would be substantial. Based on pre Brexit spending it would be around 5 billion per year, probably more. And it’s very likely that Ireland would be able to leverage a “development program” for additional subsidies from the EU after unification.
The UK is basically alone now-Ireland wouldn’t be alone with a reunification.