Final answer:
Policies and penalties deter crime when there is a high probability of being caught, strict enforcement of penalties, and a genuine fear of the consequences. However, their effectiveness varies based on their execution and the social context.
Step-by-step explanation:
Laws, policies, and their associated penalties are effective at deterring crime when certain conditions are present. These include the probability of being caught, the probability of the penalty being enforced, and the perceived severity or fear of the penalty. Research has shown that an increase in the likelihood of apprehension, such as through enhanced policing strategies, can reduce crime rates. Similarly, longer sentences for certain crimes, like gun crime, have correlated with a reduction in those crimes. The removal of lead from gasoline in the 1970s and a subsequent drop in crime rates is another example of how broader social policies can affect crime rates indirectly. However, some programs like 'Scared Straight' may not have the intended deterrent effect and can actually lead to an increase in criminal behavior. Ultimately, while penalties can act as a deterrent, the effectiveness of such measures is dependent on a combination of factors relating to both the likelihood of enforcement and the individual's assessment of the risks involved in committing a crime.