The broken windows theory is the idea that serious and violent crime can be reduced in an urban area through the strict enforcement of lesser crimes such as graffiti, skipping subway fare, and vandalism. It was first drawn up in the early 1980s. Though successfully implemented in many localities, most famously in New York City, the theory has its critics as well.
James Wilson and George Kelling, two American social scientists, published a magazine article in 1982 that argued a building with several broken windows already is prone to have more windows broken by vandals. They said this building is also going to be more likely to be broken into and further vandalized, or even become a home for squatters. Their point was that fixing those first broken windows would prevent the escalation of damage to the building. Wilson and Kelling's idea drew a lot of debate and soon came to be known as the broken windows theory.
At its core, the idea relies on a trio of sociological theories - conformity, the effect of monitoring, and the concept of signaling. Conformity is the idea that people tend to do what others around them are doing. Someone walking down the street eating a hamburger, for example, is less likely to throw the wrapper in a trash can if the sidewalk is already strewn with hamburger wrappers from other people who have chosen to litter. An area clean from litter indicates to a person that there are rules against littering and that they are followed, monitored and enforced. In districts where there cannot be a constant law presence, things such as litter-free sidewalks signal that there is nevertheless an orderly environment being maintained.
Broken windows theory was applied in New York City beginning in 1984, when Kelling was hired as a consultant and put his ideas to the test. Graffiti in and around the city subway system was focused on, as well as the practice of skipping subway fares. Rudy Guiliani, who was elected mayor in 1993, embraced the strategy and expanded it into a larger zero-tolerance policy. In addition to fare skipping and graffiti, law enforcement focused on stopping other minor crimes such as public intoxication and the unsolicited windshield washing of stopped cars by homeless people.
As a result of New York's efforts to enforce the tenets of broken windows theory, the levels of both petty and serious crime in the city dropped tangibly through the 1990s and 2000s. Similar success has resulted in other places where the theory has been applied, including cities in New Mexico, Massachusetts and the Netherlands. Despite such evidence, criticism of broken windows theory remains, however.
The biggest concern among critics is that there is simply a correlation between stronger enforcement of petty crimes and decreased serious crimes, rather than a direct causation. In the case of New York City, there were a number of coincidental events that took place around the same time that the theory was implemented that critics argue could account for the drop in crime. Peer-reviewed cases both for and against broken windows theory continue to be made into the 21st century, as more and more cities adopt the approach.