As far as Scotland is concerned, the Prime Minister seems well satisfied with the Prime Minister’s performance. Jousting with Angus Robertson of the Scottish National Party in the Commons yesterday, David Cameron declared flatly: “We have delivered on all of the promises that we made.”

The preposition alone invites comment. If by “we” Mr Cameron means the present Government, he is entitled to his opinion. If he means somehow to speak for himself, Ed Miliband and Nick Clegg, signatories to the famous (or infamous) “vow”, explanations are in order.

Together with the SNP, Labour and the Liberal Democrats have proposed dozens of amendments to the Scotland Bill. Each has been rejected. Mr Cameron might wish to draw a line under constitutional business, but such obduracy is unwise. Almost exactly a year ago, this newspaper argued that independence should be rejected, but with the strict proviso that those promising reform would be held to account. Where do we stand?

Here, for example, is the Labour Party arguing that all VAT revenues should be assigned to Holyrood, thus devolving £5 billion and allowing, so it is claimed, for the design of Scotland’s own social security system. The SNP is not impressed, but Mr Cameron can hardly maintain that no challenge has been made.

The same could be said, obviously, about the Nationalists’ persistent efforts to extract more powers. Among other things, the SNP continue to argue that a veto over welfare reform is implicit in the Bill. Scottish ministers are also unhappy about financial arrangements for the new dispensation.

The Prime Minister might say that Nationalists would complain no matter what. Given the numerous amendments proposed, there are risks, nevertheless, for a government with a single Scottish MP. Why so inflexible? Why maintain that the Smith Commission recommendations are being implemented “in full” when dissent is widespread?

Professor David Bell’s analysis for Sir Tom Hunter’s foundation, with a foreword from its sponsor, attempts cool reason. Has “Smith” been delivered? Yes and no, says Sir Tom. The negative applies to welfare powers. There is the reminder too that “there is no new money” and that Scotland could be worse off once every administrative consequence of the Bill has been felt.

Professor Bell shows, meanwhile, that independence would have been no panacea, thanks principally to collapsing oil prices. Tax increases, spending cuts and haggling over debt – in whatever mixture – would have followed. The currency and pensions could also have left a Scottish government with headaches.

Professor Bell is clear that, where welfare is concerned, the Bill is not “Smith”. He also indicates that tax powers will not give Edinburgh the flexibility in “subtle ways” enjoyed by chancellors. Nevertheless, his analysis inspires Sir Tom to urge us all to “move on, move forward, and use the powers we have”.

There is, as things stand, no alternative. This need not mean that Mr Cameron’s template is the last word. Alun Evans, the former Scotland Office director, argues that this is precisely the time for Westminster to be making a “big, bold offer” of home rule, both to forestall the SNP and to meet the aspirations of a majority of Scots.

The Prime Minister seems in no mood to listen. History suggests that is foolish. If Professor Bell is correct, if independence would have been fraught with difficulties, Mr Cameron should consider the federalist alternative seriously.