Center for Problem-Oriented Policing

Understanding Your Local Displacement Potential

There are several things you should consider during the formulation of your POP project as it relates to displacement and diffusion. This guide contains only a general description of displacement and diffusion. Because displacement and diffusion take various forms as they relate to different problems and locations, you need to combine the basic concepts of displacement and diffusion with a more specific understanding of the problem your project will address. A thorough analysis of your local problem will help you more accurately predict the likelihood of displacement or diffusion and accommodate it in your response strategy. Use the problem analysis triangle to help you understand your displacement potential.

† For a discussion of the problem-analysis triangle, see step 8 of Clarke and Eck's (2005) Crime Analysis for Problem Solvers in 60 Small Steps.

Analyzing Offenders

To assess the possibility of displacement and diffusion effects, it is important to understand the characteristics of the offenders your response will involve. Generally, you need to know how offenders benefit from the problem behavior and whether they are opportunistic or driven by stronger motivations. You also need to identify any individuals or organizations that could control offenders’ actions (e.g., handlers). Knowing about handlers helps you better assess the likelihood that offenders will displace their problem behavior to other times and places in addition to helping you identify potential responses to the problem. In regards to offenders, some of the questions you need to ask and answer include:

  • How are they rewarded for engaging in the problem behavior at that time and place?
  • How dependent are they on the problem behavior?
  • Does it provide economic sustenance for them or others in the community?
  • Do they have the resources to travel to new locations?
  • Are they familiar with other places to engage in similar behaviors?
  • Do they have the skills or resources to engage in other problem or crime behaviors that provide similar benefits?
  • Do they have the ability to acquire new skill sets and are they likely to do so?
  • Do they have other legitimate opportunities to achieve the rewards provided by the problem or crime behavior?

Analyzing the Location

To better anticipate and determine displacement and diffusion effects, you also need to consider the location of the problem your project will target. Using the principles of when and where displacement is likely to occur discussed in the previous section, you need to analyze areas near your response zone. In doing so, seek answers to the following questions:

  • Are there crime targets in areas nearby that provide similar benefits for offenders?
  • If so, are they adequately protected or are they vulnerable to crime?
  • How far is the potential new crime location from the response area?
  • How easy or difficult is it for offenders to travel to the new location? For instance, are there natural or manmade barriers such as ponds, rivers, lakes, interstates, or roadblocks that would impede travel to those locations or are they easily accessible through open and direct routes of travel? Are other sources of public transport available, such as buses and trains, to the potential new location?
  • Is the new location controlled by other offenders such as drug dealers, gangs, pimps, or organized crime members?
  • If your project response is implemented only during specific time periods, how likely is it that the crimes will take place during other unprotected times? For example, do those other time periods provide similar opportunities for crimes to occur such as the convergence of victims and offenders without sufficient guardianship?

Analyzing Victims

Understanding the victims can help prepare you for the possibility of displacement and determine the impact of your project in the assessment phase. You need to know who the victims are, why they are victims, and the harms they incur. With regard to victims, seek answers to the following questions:

  • Who is being victimized?
  • What factors facilitate their victimization?
  • Are any of the victims repeatedly victimized more than others?
  • Are they also offenders?
  • Are they a vulnerable population such as children or the elderly?
  • What are the nature and extent of the damage they experience?
  • Do they live or work in the problem area, or do they come from other places to that location?
  • If so, what brings them to that location during the times of victimization?

† To learn more about determining the extent of repeat victimization, see the Problem-Oriented Guides for Police Problem-Solving Tools Series No. 4 entitled, Analyzing Repeat Victimization.

Collecting Information

To answer the above questions, you need to gather information from a variety of sources. It is better to collect information from multiple sources because it increases the accuracy and breadth of your understanding. In some instances displacement or diffusion may fall outside your jurisdiction. In these cases it may be useful to collaborate with other departments (such as acquiring data from them) to fully gauge displacement or diffusion effects. Following are some information sources that could be useful in understanding your displacement potential:

  • Citizen surveys
  • Informal discussions with community members
  • Organizational or departmental intelligence
  • Calls for service records
  • Criminal histories
  • Regular observations
  • Interviews with line officers and investigators
  • Interviews with other government agents such as probation and parole officers, fire rescue personnel, and school personnel
  • Interviews with religious leaders, business merchants, and community organizations.

Putting it Together

Once you develop an in-depth understanding of your displacement potential, you can better predict the likelihood of it occurring, the types that might occur, and where it is likely to go. This understanding allows you to accommodate the possibility of displacement in forming your response and makes it easier for you to evaluate the influence of displacement and diffusion effects during the assessment of your project.

Planning Your Analysis

To carry out your analysis you need to identify the area or boundaries within which your response is targeted (i.e., response area), an area to examine for the presence of displacement or diffusion (i.e., diffusion/displacement area), and a third untouched area to compare (i.e., control area) any changes observed in both the response area and the displacement/diffusion area. Focus your analysis on the various forms of displacement and allow enough time from the point at which the response was implemented for it to appear. Displacement may not occur immediately following the implementation of the response but may gradually emerge as time passes.

In conducting your analysis you need to identify the volume, severity, and harm of any displacement effects and measure these relative to the gains achieved by your response. If your project does not result in any reductions in the targeted area, there is no need to analyze for displacement or diffusion effects. Your analysis can help refine subsequent cycles of the scanning, analysis, response, and assessment (SARA) process or facilitate a second problem-solving project. The steps involved in the analyses should include:

  1. The volume of displacement. First, look at the amount of crime or problem behavior that moved. To do this you need to obtain a baseline measure of the behavior in the displacement/diffusion area before implementing your response. An increase in what you are measuring suggests that displacement has occurred. A decrease suggests that diffusion has occurred. What you measure should be tailored to the specific nature of the problem your project will address. The measure may be a specific crime type, but it can also include levels of calls for service, fear of crime, social and physical disorder, or nuisance behaviors such as loitering, traffic conditions, and vagrants, among others. You should also look to see whether any changes in the displacement/diffusion area are the result of something other than your response such as the removal or introduction of some separate security measure.
  2. The severity of displacement. If you determine some level of displacement occurred, see whether the severity of the displaced behavior is greater than or less than that which was prevented in the response area. For instance, if there was a reduction in burglaries in the target area but the displacement area experienced an increase in armed robberies, the severity of the displaced crime has increased. If, however, the reduction of burglaries in the target area is associated with an increase in petty larceny in the displacement area, the severity of the displaced crime has decreased. This means the project still achieved a beneficial result despite an increase in the volume of petty larceny. This is an example of benign displacement.
  3. The level of harm incurred by displacement. Third, determine the amount of harm experienced in the displacement/diffusion area as a result of the displaced behavior. This could be done in a variety of ways depending on the specific nature of your project. It might involve assessing the financial losses suffered, whether the displaced behavior has shifted to or away from a vulnerable population, or whether the displaced behavior has been disbursed to a wider pool of victims or has been concentrated on fewer victims.