When addressing the issue of raising income taxes, two objections tend to come up. The first is that the combined marginal tax rate (including PRSI and levies) is already up to 54% (see page 161 of the Commission on Taxation Report) and this marginal tax rate kicks in at fairly low incomes. Further increases in this marginal tax rate are likely to trigger increased tax avoidance and can also have negative side effects in terms of work incentives.
The second objection is that we don’t want to raise taxes on low earners because they already don’t make much money and we have to be careful about not creating poverty traps in which people are better off earning unemployment benefit than working (Suzanne Kelly’s Irish Times article on this presented some interesting calculations.)
One way to address these objections is to introduce a flax tax with a large exemption limit. This would keep the lower paid out of the tax net and keep marginal tax rates from reaching dangerously high levels. But this approach could raise additional revenue, essentially because it would abolish the 20% tax band.