I believe that things like this are simply unknowable by any rational take because we're dealing with an extraordinary complex system.
To make a statement like "These were the winners or losers of Brexit" you'd have to clone the universe at the point of the Brexit vote, change the outcome of the vote, and let this parallel universe run forward in time. Then you could compare that parallel universe to our universe and see who is better off and who not. This is, of course, not possible as far as we know and probably never will be.
Going in after some number of years and observing that certain parts of the population are better or worse off conflates a ridiculous number of things.
So, in conclusion, statements like "Brexit was bad/good for low/high income households in the UK" are always and exclusively made for political purposes. Which is OK. But let's not pretend this has anything to do with science.
On top of the argument above, there is also the issue of "chaos" with complex systems. "Chaos" means that small perturbations to the initial state of a complex system can lead to vastly different outcomes ("the butterfly effect"; also found this here via HN the other day: http://www.complexity-explorables.org/explorables/double-tro...).
So in the case of Brexit: the outcome in the cloned universe after 5 years could be very different if the pro-Brexit vote was changed to either 49.9% or 49.99%. It could also be very similar, of course.
Long term or short term, there's no counterfactual.
In the absence of a parallel universe or crystal ball, how would you know that the entities who seem to be winners after Brexit wouldn't have won twice over without Brexit? And how would you know that firms and economies that fall behind would have been more successful if "Remain" had won the day?
To make a statement like "These were the winners or losers of Brexit" you'd have to clone the universe at the point of the Brexit vote, change the outcome of the vote, and let this parallel universe run forward in time. Then you could compare that parallel universe to our universe and see who is better off and who not. This is, of course, not possible as far as we know and probably never will be.
Going in after some number of years and observing that certain parts of the population are better or worse off conflates a ridiculous number of things.
So, in conclusion, statements like "Brexit was bad/good for low/high income households in the UK" are always and exclusively made for political purposes. Which is OK. But let's not pretend this has anything to do with science.