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On Broken Windows

The Broken Window is both a fallacy and a truth. In economics, it refers the Parable of the Broken Window, also called the Broken Window Fallacy, and it deals with hidden opportunity costs.

The basic idea is that it is temping to think that a hoodlum breaking a baker’s window stimulates the economy because the baker must go buy a window from the glazier, who then can go buy additional things from others in the community and so on.

However, the fallacy part of it is that forcing the baker to buy a window has the hidden cost of the baker not buying whatever it was that the baker might have wanted to buy in the first place — perhaps a suit. So the extra money to the glazier actually comes at the expense of the tailor, and on top of it, the baker is out a window. So when hidden opportunity costs are accounted, the net effect of a broken window is negative, not positive.

There is also the broken window theory of crime, which basically states that criminal activity tends to congregate towards lesser-maintained areas of a city, perhaps because the look of dereliction makes a criminal feel less likely to be caught. A recent article that I picked up of via Bruce Schneier’s Security Blog discusses a recent student on the broken window theory. The conclusions are interesting:

The results, just now circulating in law enforcement circles, are striking: A 20 percent plunge in calls to police from the parts of town that received extra attention. It is seen as strong scientific evidence that the long-debated “broken windows” theory really works—that disorderly conditions breed bad behavior, and that fixing them can help prevent crime.


Many police departments across the country already use elements of the broken windows theory, or focus on crime hot spots. The Lowell experiment offers guidance on what seems to work best. Cleaning up the physical environment was very effective; misdemeanor arrests less so, and boosting social services had no apparent impact.

Nevertheless, I still wonder whether the broken window theory is actually a type of fallacy. For example, it is true that a single person can stand up at a sporting event to get a better view, but this does not generalize well: if everyone stands up, it is decidedly not true that everyone gets a better view. Does the same apply to broken windows? In other words, does fixing broken windows in one area correspond to a single person standing up at the sporting event? If all broken windows were fixed, would crime actually diminish or would it sustain at current levels?

Regardless of the answer to that question, I think the last sentence — and especially the last clause — is worth repeating:

Cleaning up the physical environment was very effective; misdemeanor arrests less so, and boosting social services had no apparent impact.

Sorry social scientists.

5 Responses to “On Broken Windows”

  1. Bobby Moretti Says:

    So, the only purpose of social services is to reduce crime? Not, you know, like, help people? And this seems to be a study of one city for a small period of time. Hard to control for certain city-specific things.

    I’d also be curious to read the original paper, and not this journalist’s take on it.

  2. Stickman Says:

    For us poor people who don’t know fancy phrases, please define what “social services” means in that statement. The words, when put together, makes it sound like a service that helps you talk to other people.

  3. Ryan Says:

    Stickman — A pretty good list of what qualifies as a social service is found on

    “The job site for jobs in social work, counseling, psychology, sociology, mental health, case management, employee assistance, volunteer management, substance abuse treatment, domestic violence, community development, mentoring, youth development, child welfare, developmental disabilities and all other areas of social services.”

    Usually, but not always, social services are government-funded; in my opinion they don’t often achieve their stated goals. They often consume lots of money: think DSHS in this state. Although their intentions are usually noble, I don’t respect them very much.

  4. Hoyin Says:

    The journalist who made the statement is just about as reliable as the statistician who claim that global warming leads to a drop in piracy. There are a large number of factors that affects the overall quality of life in the neighborhood. That journalist is engaging in false causality – wrongly drawing conclusions about things that don’t have a physical correlation.

    Cleaning up the physical area of a neighborhood is more multi-faceted than you (or the journalist) assume. First and foremost, community involvement is a key factor – however, that does not mean that communities that are more involved will be more aesthetically pleasing (see: Orange County, CA for counterexample) or vice versa. Next, investment by the public and private sectors. By public sector investment, maybe not your definition of social service, but it’s public service nonetheless – parks, trees, public transportation, etc. Generally, private investments will follow the flow of public money. It’s not a coincidence, private sectors are reluctant to throw money into a neighborhood that they don’t see positive return in a short/long term.

    In all of this, money talks. More money brings better law enforcements and public/private investments. Both contributes to higher land value that drives less well-off tenements out and drive down crime rate. Higher land value then brings more money and start the cycle all over again. As to whether the Lowell experiment works, the better question is: where did the hoodlums go? They moved away from Lowell, but where have they gone? They went to other neighborhood and becomes another neighborhood’s problem. If those neighborhoods follow Lowell’s example, that will simply perpetrate the cycle of passing it off. This is the type of selfishness that first drove us to this rock bottom economy in the first place.

    Of course, boosting social service will not solve the problem in its entirely either. Individuals have to be a part of the solution as well. Some people become complacent on welfare, but that does not mean that everyone who receive welfare are lazy leeches of society. All of us will hit the floor some time – welfare helps those who have the drive to help themselves. Private investment can choose who to help – the government can only choose how much to help.

  5. nordsieck Says:

    When looking at social services, it is easy to argue that they are effective; it is also easy to argue that they do no (or negative) good – there are tons of aspects.

    The most important aspect of social services to me is whether they encourage independence or dependence on the programs. This is relatively easy to determine – charities which encourage independence implement policies which decrease their number of clients (down to some minimum replacement rate). Charities which encourage dependence implement policies which serve accumulate as many clients for said charity up to its budgetary limits.

    Unfortunately, given bureaucratic dynamics, only one sort of government charity is possible.

    As for keeping down crime – I thought Gladwell was talking about New York City, and that crime went down state wide as a result – it’s kind of hard to be a criminal in a rural setting: there just aren’t enough liquid assets.

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