The latest Brexit referendum passed with barely a couple percent over the 50% threshold, despite being a major constitutional change with significant consequences for many generations to come. Likewise the referendum for Scotland to leave the UK also had a mere 50% for threshold for something that would be extremely hard to reverse.
Why is the 50% threshold considered to be the standard for such major decisions? Are there countries where the threshold is higher?
Referendum with higher thresholds are not unheard of. Swiss referendums have a double majority requirement (50% of the popular vote and succeeding in at least half of the provinces). The Montenegro independence referendum had a 55% threshold. The South Sudan independence referendum had a 51% majority and 60% turnout threshold and I think the East Timor referendum might have had something like that too.
One reason that's not that common is that a supermajority requirement also implies that a minority gets to decide the result and force its choice on the majority. It's a logical consequence and potentially a defensible procedure when you are talking about major, irreversible changes but if you state it like that it does not sit well with democratic sentiment.
