What are some of the reasons cited for the “Great American Crime Decline”?

https://www.theatlantic.com/politics/archive/2016/04/what-caused-the-crime-decline/477408/
1) What are some of the reasons cited for the “Great American Crime Decline”?
2) What factors does Zimring cite for the crime decline in New York City? Specifically, which policing tactics does he believe worked and which criminal justice policies do not work?
3) Based off of both Zimring and the Great American crime article- which factors do you believe are most
important and why?
4) Based on the factors that you chose as most important, could these things change in the future and bring back another crime wave?

compare with article attached