human
Are more store robberies committed with or without a gun?
assistant
This would be an interesting statistical question. There have been a lot of studies of this kind of thing. Here is a (quite old) academic paper titled "Murder, robbery, assault and burglary: The effects of state gun control laws" (it might be easier for you if I just summarize the results here, rather than you trying to read the original):
"When I control for all other variables and the federal discount in a model containing three variables—crime rates, the GCA, and the PLC [prohibiting the carrying of concealed weapons]—the federal discount coefficient is positive and statistically significant (0.22) at the 1 percent level. When I control for the federal discount, the PLC coefficient is positive and significant at the 5 percent level. In both models the coefficient for the GCA is negative and significant at the 1 percent level.
The results are consistent with a deterrent effect of firearms, so the GCA may reduce robberies. But the gun controls may reduce the number of people who resist when they are victims of crime, and this effect could be more important than the deterrent effect. My best judgment is that the two effects are about equally important, but more research would be useful."