Economics alone is not a contributor to crime. One can argue all day long that poverty causes one to steal... but that is only true in the absence of morality and of other options by which to provide for oneself. Poverty, historically, is more likely to cause hard work, ingenuity, and political change.
Race has never been a large contributor to crime by itself. Culture, however, is probably a large contributor. Multiculturalism has forced an entire generation to ignore each individual's worth, and to shun any shared loyalties among the artificial groups we have set up. Immigrants, rather than being absorbed into the "American melting pot" the way they were in the past, are now classified as being less than American, even after 2 or 3 generations.
A much faster pace of life, combined with unchecked greed for status is probably a larger contributor yet. No longer do we gather around and talk to our neighbors. Instead, we're all off working to purchase a bigger and shinier SUV than they have.
The largest contributor to crime, IMHO, is the lack of a family structure for many of todays young ones. Growing up without a father, and with mother off working for her new SUV, children are left alone to create role models out of the people they see on TV. Their TV role models are able to resolve complex issues in one half hour episode, and often by resorting to violence.
My conclusion... and this is only my opinion... Crime's leading cause is a greed for material goods to elevate one's status above their artificially imposed grouping, and thus receive the individual status that their grouping and lack of family structure denies them.
Our fast paced lifestyle doesn't encourage financial gains by long periods of hard work... instead an easy route (such as theft) is often chosen. Role models capable of quenching this greed for status, such as a poor, but hard working dad, aren't present. Instead, only the TV role models exist, and they just further the illusion that material goods are the key to get out of unhappiness.
For those who've decided that their social grouping is inescapable, there is always drugs.