An ever-escalating gang problem in the United States has been fought since the 1940s. And if something drastic is not done, the country is condemned to deal with a proliferation of street gangs for decades to come.

So declares USC emeritus professor Malcolm Klein in “Street Gang Patterns and Policies” (Oxford 2006), which he co-authored with Cheryl L. Maxson, a UC Irvine professor.

Klein would know. He has written 10 books on gangs since he began his studies in the early '60s - when about 60 metropolitan areas harbored gangs.

Now gangs are a concern in 4,000 jurisdictions, “from the big cities to the Indian reservations,” Klein said.

In “Street Gang Patterns and Policies,” Klein and Maxson look at the societal problems that lead to gangs and ponder the strategies for preventing their formation.

The authors attempt to undo the assumptions many have about street gangs by gathering and analyzing the available research, explaining gang migration, organization and structure.

And they assess major gang programs across the nation that aim to stop the gang activity or discourage kids from joining the 700,000 members already roaming the streets.

Before choosing a strategy for control, Klein stressed the importance of gathering the facts about the gang, such as the size, how long it's been around, the ages of members, territory and if it exists to make money through criminal activity, such as selling drugs or stealing cars. These factors then can be used to create a program unique for the area's gang problem.

“But most evidence is not taken into account when creating gang programs,” Klein said. “Most programs are run seat of the pants using conventional wisdom. They are not using what's been learned.”

The evaluations of 60 programs from around the country are largely discouraging, especially in that the creators of the programs have no idea if they are even working.

Despite years of implementation, replication and millions of dollars spent, many of these programs never check to see if they actually complete their mission of thwarting gangs or gang activity.

“It's as if it's enough to say, 'We're doing them,' ” Klein said.

Most programs concentrate on the symptoms rather than looking to change the situations that incubate gang behavior on a neighborhood level.

“Communities spawn gangs and have the potential to prevent or control them,” Klein writes. “This is where we should put our money - a great deal of money.”

He argues that there needs to be societal changes that affect the “urban underclass,” because social marginality leads to gangs.

“Gang formation is spawned in communities with poverty, discrimination, inadequate resources and where official hostility is felt,” Klein said.