It’s a Swedish term åsiktskorridor meaning opinion corridor. The band within political discourse is expected to happen, outside of which discourse is considered deviant. Its a very useful concept in describing Sweden’s post war desire for consensus building, and I don’t use it pejoratively, as some would, to criticise the lack of oxygen for extreme views in such a society. I use it normatively to describe the expectation of the parameters for acceptable discourse. It is particularly useful to describe the parameters of debate used in the UK by the BBC, which can be exploited by those operating outside it, for example by climate change deniers and those with a tangential relationship to the truth, who use publicity to normalise and shift debate towards extreme views (the related concept of the Overton window).
The problem with plan makers and plan objectors is that they now operate in barely overlapping opinion corridors. Those opposing are branded Nimbys, those promoting are accused of being dinosaurs promoting climate unfriendly policy. If you are the losing side of a plan debate demands for cllr resignation, This is stifling of genuine debate on matters of profound importance.
The post war plan making system assumed a single opinion corridor. This was broken by the onset of localism which institutionalized views outside it but with penalties for non delivery. It was further broken by planning straying from a discourse based on evidence (of housing need). It became a rule rather than a norm at precisely the point the evidence (past household formation) ceased being a useful predictor. With plan making divorced from rational evidence it has become a battle of opposing world views with a supposition of bad intent of the opposing side.
Now successful plan making effort can occur without successful maintenance of a wide opinion corridor from beginning to end. It is not just the promotion of inclusive participation. That is barely 10% of it. It is mostly about structuring a discourse on the impact of alternatives. This rarely takes place. Sites come through a developer led call for sites process, are chosen through smoke filled room meetings excluding the non ruling group and those impacted feel excluded and feel obligated not just to oppose (within the bounds of the system) but to seek to overturn that system as the only guaranteed means of success.
If the planing system is to remain democratic (as opposed to drifting further towards buying consent with favours) it needs to find ways to nurture and protect an inclusive opinion corridor for genuine realisable alternative visions of sustainable futures.