Seveal politicians and commentators have bolstered the false premise that a clearly defined third option as an alternative to independence or the status quo has yet to emerge.
In fact, last September Reform Scotland published Devolution plus, a fully researched and detailed proposal that would give the Scottish Parliament control over sufficient tax and borrowing powers to meet its spending commitments, removing the need for the block grant.
The principle of devolution plus is that each level of government should, as far as possible, be responsible for raising the money it spends.
Increasing the financial accountability and responsibility of the Scottish Parliament would lead to a much better incentive structure for politicians. And much greater attention being paid to the delivery of value-for-money public services, the balance between spending and its costs in terms of higher taxes, and how we might foster economic growth.
It similarly addresses the issue of democratic accountability and legitimacy of the relationship between parliaments for the long term.
Crucially, devolution plus contrasts with devolution-max, in which all the money would be raised in Scotland and a grant passed down to Westminster to cover shared UK services, such as defence.
Devolution plus would leave Westminster with responsibility for VAT and national insurance and devolve most other taxes to Holyrood, where the majority of expenditure takes place. It sets out a proposal for transferring to Holyrood additional powers over social protection, including welfare benefits.
The fundamental defect of the current devolution settlement is the lack of financial responsibility it gives to the Scottish Parliament.
Devolution plus is a credible and fully thought-through third option that seems to be in tune with what opinion polls suggest most people in Scotland want.
We believe it is the best way forward and it should be a central part of the debate on Scotland’s constitutional future.
• Ben Thomson is chairman of Reform Scotland.