The Institute for Public Policy Research, centre-left oriented think tank, has published an enormous body of research into the composition of Britain's immigrant communities. Where they live, where they came from - a huge cache of facts to fuel a debate that is long on speculation and opinion.
Sadly, you have to pay to read it all. (Think Tank wonks gotta to eat too.)
Happily, swaths of it are available on the BBC, for free.
Sound of muted cheering for public service broadcasting.
