Why do non-governmental organizations tend to publish non peer-reviewed "grey" literature? Is there any reason why most non-governmental organizations (NGOs) tend to publish non-peer reviewed literature? I have seen some NGO scientists as co-authors, even in some important papers, but most of their production is reports which are not peer-reviewed. While it is true that most NGOs do not do basic research, some of their reports could easily be converted to reviews, and some of their projects to applied research.

Do they want to avoid peer review for political reasons in order to be able to convey the message they want? In my view their message would be much stronger if it came from a peer-reviewed article. Is it also a matter of time as peer-reviewed articles take a long time to get published?
I can think of a couple of reasons:


Peer review is slow. NGOs want their paper to influence policy now, not in one or two years from now.
Peer review journals have a different audience than grey literature. NGOs typically want to communicate with people like policy makers or journalists, and these are less likely to read peer reviewed journals.
Related to point 2: in order to effectively communicate with their intended audience they need a different style of writing and presenting their arguments than what is common and acceptable in peer reviewed journals.