The long-term public finances will depend on the performance of the Scottish economy.
"Independence would give the Scottish government additional powers – currently held by the UK government – that could potentially help it to grow the economy by increasing the size of the working age population (most notably via immigration policy), boosting labour force participation and employment rates (for example, through welfare reforms), and improving productivity (for example, through changes in regulation).
Improving productivity would likely be the most important, as productivity growth is the main driver of long-term economic growth, and is where Scotland performs most poorly compared with the other small nations of north-western Europe...
Whether an independent Scotland would be likely to implement growth-enhancing policies that would enable it to strengthen its public finances in the longer term is an open question. Surveys showing greater trust in the Scottish government may give it greater ability to take the sometimes politically difficult decisions that growth-enhancing reforms can require. Whether that trust would be sustained post-independence is unclear.
What is clear though is that to avoid higher taxes or lower spending continuing in the longer term, stronger growth would be needed post-independence...."