Let's take a census on will for united Ireland
There has been a huge amount of media coverage on a border poll, due to the EU referendum result.
Successive secretaries of state have said conditions have not been met for this.
I believe that to really have a good idea if the people of Northern Ireland would like a border poll you would need to include a question in the next Northern Ireland census in 2021.
The question should be: "If the economic conditions were favourable, would you vote for a united Ireland?", or something to that effect.
If the majority of the census returns provided a favourable result, then the Secretary of State at that time would have no other option other than pushing for a proper border poll.
The timing would be significant, in that the people would be providing their viewpoint on the 100th anniversary of the formation of the Northern Ireland state.