Free movement will end when the UK leaves the European Union in March 2019, the Immigration Minister Brendan Lewis told the Today programme on 27 July. As usual with Brexit, it pays to read the small print. In fact, the actual text of the government’s commissioning letter to the Migration Advisory Committee (MAC), published says:

“As part of a smooth and orderly transition as we leave the EU, the second phase of our immigration proposals is based on a temporary implementation period to ensure there is no cliff-edge on the UK’s departure for employers or individuals…During this period there will also be a straightforward system for the registration and documentation of new arrivals.”

In other words, ending free movement in 2019 doesn’t mean actually ending free movement; it means that new arrivals from the EU will, unlike at present, have to register. From a bureaucratic point of view this makes perfect sense; whether, however, it will convince the public that we are “taking back control” of immigration is less clear.

Moreover, there is a risk that we will end up with the worst of both worlds. If the EU27 take us at our word that free movement will indeed end in 2019, the chances of securing what government and business are now clearly asking for – a “temporary implementation period” during which very little changes, and we remain full members of the Single Market – will be much reduced. So, despite Amber Rudd’s claim that there will be no “cliff edge” for employers when we leave the EU, we are no nearer clarity on what the government’s strategy is for ensuring that – probably because it doesn’t yet exist.

The other key point about the commissioning letter to the MAC is what it doesn’t say. The centre-piece of the government’s overall migration policy is, of course, its objective to reduce migration to below 100,000. Now, if you were a government minister, and you had, on tap, a group of economists with expertise in immigration and labour market policy, and wanted to commission a year-long research project, you’d think you might ask them at least one of the following questions. Is this a sensible target? Is it realistic? What would be the impacts of hitting it? How could you achieve it in the most efficient and effective possible way?

Instead, the target is not even mentioned – merely vague language about reducing migration to “sustainable” levels, which from an analytic perspective is entirely meaningless. If this means that the economically illiterate and damaging target – already effectively a dead letter since the election – is now to be given a decent burial, so much the better.

What will the MAC research tell us about the impact of free movement? Probably not a lot that we don’t already know from previous work, as summarised in the Coalition Government’s “balance of competences” review: which found, unsurprisingly, that free movement had been beneficial to the UK economy and evidence of any downsides were fairly limited.

Since she didn’t like what the evidence actually said, Theresa May (then Home Secretary) did her best to suppress the report. Let’s hope Amber Rudd – who post-election appears to want to set a more sensible course – is more interested in evidence-based policy making than her predecessor (and boss).

On the positive side, a lot can change in a year. Perhaps by then the UK will be ready – on the basis of the evidence and analysis produced by the MAC, and by external researchers – to have a sensible debate on what a post-Brexit immigration policy might look like. As I’ve noted previously, with migration falling, the economy slowing, and public services visibly feeling the pinch, it may be much easier to secure broad public consent for the liberal and open migration policy – to both EU and non-EU citizens – the UK actually needs.

Jonathan Portes is Professor of Economics and Public Policy, King’s College London, and Senior Fellow, UK in a Changing Europe. This piece was originally published in the Telegraph.