math 105

Imagine data that showed the number of violent crimes per year and the number of churches (of all denominations) in 100 U.S. cities. Research has shown that these two variables are highly correlated; that is, cities that have more churches also tend to have higher crime rates, and cities with fewer churches tend to have lower crime rates. Does this result indicate that churches cause crime, or that crimes cause churches to be built? What else might be going on to create this relationship?