When John Swinney presented his draft budget last October, he spoke of maintaining plans to increase further education funding.

The figure mentioned was £526 million and the claim, as far as it went, was accurate. What the Finance Secretary neglected to mention was the punishment inflicted on the sector in the space of five years.

As Colleges Scotland will remind you, funding stood at £555.7m in 2011-12. Even given the modest increase promised by Mr Swinney, the total awarded will still have fallen by almost £30m in cash terms and £67m in real terms by the time the next budget is being prepared. For colleges this is, in anyone's language, a challenge.

Amalgamations were supposed to provide a solution. Institutions "volunteered" for these en masse with a view, as Audit Scotland reports, to securing "high-level benefits". With the Scottish Government and the Scottish Funding Council pressing for reforms, the number of colleges was cut from 37 in 2011-12 to 20 in 2014-15. In theory, there would be "reduced duplication, improved engagement with employers, better outcomes for students and financial savings of about £50m".

The magic word, as ever in modern government, was "efficiencies". It expresses a fine aspiration. Too often, however, it also acts as a handy accounting device for finance ministers short of revenue. First, reduce the budget, then rely on those long-hidden efficiencies. For those on the receiving end, it generally leads to the simplest expedient: staff cuts. According to Audit Scotland, colleges have coped with stringency thanks almost entirely to job losses.

But why not? Irrespective of any other argument, amalgamations must surely reduce duplication and staffing levels. Unless something goes badly wrong, savings must be inevitable. Audit Scotland does not dispute the theory. It says simply that in this case, absurdly, we just do not know.

All the upheavals, all the controversies: surely these are justified? What happens, for that matter, when the last savings have been made in staff costs? Audit Scotland observes, mildly in the circumstances, that it is "unclear what savings have been achieved in addition to reduced staffing costs and what the full costs of the merger process are as there are no systems in place either at individual colleges or centrally to collect this information".

In other words, the biggest programme of reform seen in further education in a generation has been carried out without anyone bothering to monitor or assess the effects. "It is also unclear," as Audit Scotland would have it, "what progress there has been in achieving some of the wider benefits expected from the mergers".

Bluntly, we do not know whether it has all been worth it. We do not know if the promised efficiencies have been fool's gold. Further education, crucial to employment, the economy and the life chances of thousands, has been turned upside down. And all because those who ordered and carried through reforms simply assumed they would work?

That would be the charitable assumption. The disturbing alternative is that no one cared enough to test the effectiveness of their handiwork. If the Scottish Government has an answer to Audit Scotland's findings, it should be provided forthwith.