Don't you watch all those detective shows?

Actually, the move to suburbia was middle and upper America's response to crime of the 1960's. It removed the "opprotunity" part of the equation.

Pervasive public transport allowed roving gangs of young people to move easily from one neighborhood to another in the "inner cities" of the 1960's. Older people don't commit as many crimes because --well they are old & slow, and perhaps they have developed a set of morals (except for Enron execs). So the violent crimes problem is mostly one of gangs of unemployed males.

It is the expansive highway system and the need for expensive cars that keeps large gangs from forming in Suburbia (outside of school grounds). Recently, we have advanced to "gated" communities. Why?

I believe the answer to your questions can be partially derived from studying Genetics and Memetics:  Googling Hans Selye's General Adaption Syndrome [GAS] and the Environment of Evolutionary Adaptedness [EEA] which obviously includes 'inclusive fitness'.  Evolved behavioral switches, which can be probabilistically extended to larger social groupings, combined with entropic decline forms the basis of discussions by Diamond, Tainter, Hanson, et al--what I call the Thermo-Gene Collision.

Isaac Asimov's Foundation concepts of predictive collapse and directed decline uses Hari Seldon's psychohistorical analyses to mitigate decline.  I have no proof that any governmental orgs are using supercomputer simulations to do the same--it remains beyond my discovery-- yet historical trends seem to point to various manipulations.

We have had long ranging debates on certain Yahoo forums about this Foundation possibility and ultimately agreed to  disagree about the existence of such an entity.

Evolutionary inevitability vs. human exercise of freewill is obviously a volatile topic, yet Overshoot and Dieoff occurs constantly in Nature.  I believe humans will be very, very lucky if we can optimally mitigate our own decline-- the odds are against us when one considers the totality of the forces arrayed towards a plague specie.

Here are a few links to get you started:

http://www.objectivethought.com/articles/psychohistory.html

http://www.kuro5hin.org/story/2006/4/17/194059/296

Thus, there is a very good reason Asimov's Foundation Series was voted the best Hugo Science Fiction Award-- a tantalizing glimpse of a possible Rosetta Stone to predict how masses of humans will behave and how to control them.  Isaac Asimov, Robert Heinlein, Aldous Huxley, H. G. Wells, Darwin, Malthus, et al, were way, way ahead of their time.

Peakoil and climate change is just thermodynamics [physics in action], the real interesting stuff is on the human genetic and behavioral side.  Googling Foundation brings up everything from Al-Qaeda [the base or foundation!] to Joseph Caldwell [a nuclear weapons scientist's prediction of our demise in a full-on nuclear gift exchange to less than 500 million]:

http://en.wikipedia.org/wiki/Al-Qaeda
http://www.foundationwebsite.org/
http://www.foundationwebsite.org/WhoAmI.htm

Bob Shaw in Phx,Az  Are Humans Smarter than Yeast?