Can you provide documentation for that assertion? One officer per car is standard here because of pure economics; extra vehicles cost a lot less than extra people. And the officers I know feel a lot more vulnerable working alone, which makes them a lot more likely to be ultra-defensive.
Yes, here is some documentation:
Carlene Wilson. "Research on One-and Two-Person Patrols: Distinguishing Fact from Fiction." South Australia: Australasian Centre for Policing Research. 1991.
Scott H. Decker and Allen E. Wagner. "The Impact of Patrol Staffing on Police-Citizen Injuries and Dispositions." Journal of Criminal Justice. 1982. Vol. 10. p. 375-382.
Journal of Criminal Justice:
http://www.elsevier.com/wps/find/journaldescription.cws_home/366/description#description
Statistics.... well, I am as skeptical as they get on statistics.
The Journal seems to have the most information on the psychological implications of this phenomenon.
I had heard of this years ago, but dismissed it, not because I didn't believe it but out of ignorance of the fact that it may one day have some bearing in my life. The next I read of it was in Malcolm Gladwell's book "Blink" (which I highly recommend), this was after I had been arrested but before my DHS /FBI interrogation so, naturally, paid attention.
I am going to try to find the exact cities that are enforcing this here, as I have heard which ones they are (in my readings) but have not made contact myself.
I would have to agree that in that line of work you would think one would feel safer working with another person. Lets just say these stats are true...could it also be that less mistakes are made because one would be more passive, in otherwords, inaction? Therefore, not being defensive enough?
Hope this Helps,
Tanya