text: Unionists claim this would be difficult to sustain after independence, without raising taxes, as North Sea oil revenues will decline in the longer-term, although others argue that a culture of maintaining a comparatively large public sector and welfare state in Scotland is also an impediment to more substantial and competitive economic growth seen in other nations like Ireland, and that the surplus oil revenue ought to have been invested in a Sovereign wealth fund like The Government Pension Fund of Norway, with some wishing to reduce public spending and devolve more fiscal powers to the Scottish Parliament in order to address this issue within the broader framework of the Union.