We certainly do not need to read studies to find that the middle class is bleeding from taxation. We can see this all around us.
What is outrageous is that the taxes are going towards a big black hole. They support a needless part of the wider public sector, trade unionists and mismanaged utilities.
As for the services we get in return from the state, they have either degraded or collapsed.
The only thing that's shocking is that the former middle class continues to pay or tries to pay its taxes and hasn't yet defaulted.