An independent Scotland would have faced an even bigger budget deficit than previously thought.
The Institute for Fiscal Studies' updated assessment shows Holyrood would’ve had a £10.6bn black hole by the end of 2016/17, more than the £8.2bn initially forecast.
By the end of the decade, when the UK as a whole is forecast to run a surplus, Scotland is likely to have a deficit of £12.8bn.
"Oil and gas revenues are now forecast to be lower, following further falls in expected oil prices, and cuts to the tax rates levied on oil and gas producers," it said.
"Given the majority of these revenues would have come from operations in Scottish waters, the impact of these further declines on the Scottish deficit is proportionately much larger than that on the deficit of the UK as a whole."
However, it added that independence could let Scotland whittle down its debt costs by negotiating a good deal with the UK.
Independence could also boost economic growth, allowing politicians to adopt policies which will boost the Scottish economy, and increase their power over tax and spend.
But in reality, if an independent Scotland faced a budget deficit like those outlined, the IFS said spending cuts and tax rises would be needed to put the public finances on firmer footing.