evidence: Currently, the only significant revenue raising undertaken by Stormont is regional rates, a property tax paid by households and businesses. Since 2015, Northern Ireland has had the power to cut corporation tax, albeit the treasury first needs to be satisfied the executive's finances are on a sustainable footing. [...] "Our analysis shows that, hypothetically, had Northern Ireland devolved income tax 20 years ago, for example, the NI budget would have been favourably impacted in the early years, but then significantly adversely affected, in the years following the financial crash," he said.