I'm not talking about government run pensions, but about private retirement accounts or other investments owned by retirees.
There again, there is tail risk. You may not be made whole if the pension custodian is bankrupted by fraud, seized by the government, or otherwise subject to accident.
There's an easy empirical way to assess this. Ask how common are violent political revolutions and what happens to financial products sold before the revolution. Did the All-Russia Insurance Company continue to pay out on policies after the 1917 Revolution? The headquarters building was seized by the Cheka and I believe the owners and executives were exiled or liquidated. What happened if ...
Lecture at youtube.
Sorry - haven't watched it yet so no summary, but I expect it to be fun.