I have been saying this for years.
I've been critically observing the BBC for years and noted the bias to the left - now a report confirms this with statistics.
Clearly I'm not surprised as on any given day a simple analysis of the BBC's output will show the following:-
1. Guardian quoted more than any other paper.
2. Right wingers given 'harder' interviews to left wingers.
3. Negative attitude to government 'CUTS' (if only they were cutting!)
4. More interviews and presentations from left wing think tanks etc
5.More interviews with left leaning members of the public.
6. Too ready to knock the bankers and the rich. ( what a cheek from the rich privileged BBC!)
The BBC IS Institutionally bias and will remain so until the licence fee goes.