I believe Mr. Barton is a former or current member of Mckinsey's consulting; some of their ideas work, and some do not:
http://dealbook.nytimes.com/2013/09/02/in-a-new-book-mckinsey-co-isnt-all-roses/?_r=1

Past experience in Canada shows P3 do not generally live up t their hype as presented by Government representatives.
See: Public Service Private Profits by Prof. Loxley.
There certainly is a problem for pensions funds and such, finding that secure investment; but, before they came along governments did the same thing without the intermediation of privately controlled capital. 
How the dispersal of private capital into the public sector proceeds and the ramifications there in, are the crux of the problem.
Middle men abound in these things, and the line-up to taste the taxpayer largesse gets longer and longer.