How do police officers help local economy?

They are part of the system that enables efficient flow between buyers and sellers. They enforce the laws that allow business' to run smoothly. Buyers can purchase products from sellers knowing that they are not going to be taken advantage of, in a simlar manner sellers have a means of dealing with theft or vandalism to their property. Police in general act so that citizens are treated fairly and their rights are preserved, without this very little would run smoothly in society, including local business.