Concentration of Crime

The high concentration of crime in a handful of cities is clear. What is not clear, however, is why crime levels are high in particular places. Using crime victimization data from thirty-two Mexican cities, I test one proposition and develop another. First, I show that Zipf's law fits to a certain degree the distribution of crime victimization and fear of crime. Second, I argue that these patterns are due to opportunities to commit crimes that are created not only by the spatial-temporal convergence of potential victims and offenders, but to the principle of least effort, which helps explain urban development processes. In this regard, more and better conditions of production in a city mean not only more jobs and wealth, but also more crime victims. This suggests that urban crime is not only predictable, to some degree, but also a problem associated with the forces of urbanization. KEYWORDS Cities; crime; fear of crime; Mexico Mexican cities differ in many respects, but their similarities could be summed up under one heading: a high prevalence of crime. This is why, among other things, Mexican civil society and the federal government have engaged in heated debates about the functioning of the national crime prevention program, with particular attention being paid to the geographical definition of priority areas (i.e., demarcaciones prioritarias) for crime prevention. The premise of the program is that social crime prevention works better in areas with a high risk of crime (i.e., municipalities with high levels of homicide rates). The debate about the geographical definition of priority areas starts with the fact that the methodology for the selection of these municipalities is unclear (Mexico Evalua 2015). The two main disagreements concern whether the selected areas are actually the most dangerous areas, and whether homicide rates should be the only indicator of the need for social crime prevention policy action. What this debate shows, among other things, is that Mexico has a crime data problem. Although Mexico has some administrative records of crime at the municipal level, there currently exist very few crime data using units of analysis greater than (i.e., city or metro area) or smaller than (i.e., neighborhood) the level of the municipality, which has led to some of this definitional debate. Although the debate has largely focused on addressing problems in the existing data, two additional problems have not yet been debated. One is that the only measure of the impact of the crime prevention program is the rate of victimization or crime prevalence at the national level. Therefore, this measure does not say much, if anything, about the distribution of crime in particular locations within the country. One city with 1 million victims can be confused with ten cities with 100,000 victims, as long as they have the same crime prevalence. These areas are entirely different from a public policy perspective, however. In addition, the current budget formula in federal crime prevention policy prioritizes

Objective Research demonstrates that crime is concentrated. This finding is so consistent that David Weisburd refers to this as the “law of crime concentration at place”. However, most research on crime concentration has been conducted in the US or European cities and has used secondary data sources. In this study, we examine whether the law of crime concentration applies in the context of sub-Saharan Africa using primary data. Methods A crime victimization survey was used to collect data in the city of Kaduna (Nigeria). Using these data, the concentration of crime (breaking-and-entering and domestic theft) was examined at the household, street segment, and neighborhood levels. Specifically, variants of a Lorenz curve and the Gini index (GI) were used to examine whether crime concentrates at these different spatial scales and if such concentration reflects anything beyond the spatial distribution of opportunity for these types of offenses. Results Crime was found to concentrate at a...

Extensive empirical evidence shows that crime concentrates in place, with these findings being important for helping to target police resources. Little is known, however, about whether these crime concentration areas are where crime increases the most during a period of crime increase. Using data from the seven largest cities in the state of Rio de Janeiro, Brazil, we show that during a period of crime increase the locations most responsible for the increases were the micro-places where crime previously concentrated. We argue that the increases in crime in areas of crime concentration were mainly due to these places offering stable favourable conditions for crime. The study introduces a simple indexthe Crime Concentration Dispersion Index-that helps police agencies determine where to target resources during a period of crime increase and offers results that provide an important Latin American urban perspective to the literature on crime concentration.

Background: Considerable research shows that crime is concentrated among a few victims. However, no one has systematically compared these studies to determine the level of concentration and its variation across studies. To address this void in our knowledge of repeat victimization, we conducted a systematic review and meta-analysis of the evidence that crime is concentrated among victims. Methods: We distinguished between studies of victimization prevalence, which examine both victims and nonvictims, and studies of victimization frequency, which only examine subjects that were victimized once or more. We identified 20 prevalence studies and 20 frequency studies that provided quantitative information sufficient for analysis. We organized data using visual binning and fitted logarithmic curves to the median values of the bins. Results: We found that crime is concentrated within a small proportion of the subjects in both the prevalence studies and frequency studies, but also that it is more concentrated in the former. When we compared studies of business victimization to studies of household victimization, we found that victimization is more concentrated among households than among businesses in prevalence studies, but that the reverse is true for frequency studies. A comparison between personal and property victimizations shows that the patterns of re-victimizations are similar. Crime is more concentrated in the United States compared to the United Kingdom in prevalence studies, but the opposite is true when frequency studies are examined. Finally, the concentration of victimization changes over time for both the US and the UK, but the nature of that change depends on whether one is examining prevalence or frequency studies. Conclusions: Not surprisingly, our systemic review supports the notion that a large proportion of victimizations are of a relatively small portion of the population and of a small portion of all those victimized at least once. There is no question that crime is concentrated among a few victims. However, there is also variation in concentration that we also explored.

Background: That crime is concentrated at a few places is well established by over 44 studies. This is true whether one examines addresses or street segments. Additionally, crime is concentrated among offenders and victims. Many physical, biological, and social phenomena are concentrated as well. This raises a question: is crime more or less concentrated at places than other phenomena? If it is not, then crime concentration maybe the result of standard ubiquitous processes that operate in nature. If crime is more or is less concentrated than other phenomena, then researchers need to ask why. Methods: We synthesize results from three systematic reviews and review other literatures to provide preliminary answers. Results: We find that although crime is more concentrated at addresses than other spatial units, this is due to the fact that more addresses have no crime than is true of larger units. When only places with one or more crimes are examined, place crime is no more concentrated than other spatial unit crime. Crime appears to be concentrated at places at about the same level as it is concentrated among offenders or victims. And crime concentration does not appear to be peculiarly concentrated compared to non-crime related phenomena. Conclusions: The concentration of crime at places is unexceptional, and should be treated as one manifestation of a general tendency of things to be concentrated.

Background: Despite the increasing awareness and interests about the importance of crime concentration at places, scholars have not comprehensively synthesized the body of evidence related to this thesis. We conduct a systematic review and meta-analysis of the evidence that crime is concentrated among places. Methods: We identified 44 studies that empirically examined crime concentration at place and provided quantitative information sufficient for analysis. We organized data using visual binning and fitted logarithmic curves to the median values of the bins. We examine concentration in two conditions: when all places are studied (prevalence), and when only places with at least one crime are studied (frequency). Results: We find that crime is concentrated at a relatively few places in both conditions. We also compared concentration for calls for services to reported crime incidents. Calls for services appear more concentrated than crime at places. Because there are several ways place is defined, we compared different units of analysis. Crime is more concentrated at addresses than other units, including street segments. We compared crime concentration over time and found less concentration in 2000s compared to 1980s and 1990s. We also compared crime concentration between U.S. and non-U.S. countries and found more concentration in U.S. Finally, violent crime is more concentrated than property crime. Conclusions: Though we systematically reviewed a comprehensive list of studies, summarizing this literature is problematic. Not only should more systematic reviews be conducted as more research becomes available, but future inquiries should examine other ways of summarizing these studies that could challenge our findings.

We examine the distribution of crime across street segments in Cincinnati (proximal places), and then proceed to look at the distribution of crime at addresses (proprietary places) within the segments. We find that for a substantial proportion of the proximal places, crime is concentrated at a few proprietary places. This indicates that the address is potentially implicated in the cause of crime events. Theoretical and practical implications follow.

Background: That crime is concentrated at a few places is well established by over 44 studies. This is true whether one examines addresses or street segments. Additionally, crime is concentrated among offenders and victims. Many physical, biological, and social phenomena are concentrated as well. This raises a question: is crime more or less concentrated at places than other phenomena? If it is not, then crime concentration maybe the result of standard ubiquitous processes that operate in nature. If crime is more or is less concentrated than other phenomena, then researchers need to ask why. Methods: We synthesize results from three systematic reviews and review other literatures to provide preliminary answers. Results: We find that although crime is more concentrated at addresses than other spatial units, this is due to the fact that more addresses have no crime than is true of larger units. When only places with one or more crimes are examined, place crime is no more concentrated than other spatial unit crime. Crime appears to be concentrated at places at about the same level as it is concentrated among offenders or victims. And crime concentration does not appear to be peculiarly concentrated compared to non-crime related phenomena. Conclusions: The concentration of crime at places is unexceptional, and should be treated as one manifestation of a general tendency of things to be concentrated.

Objectives. Investigate the spatial concentrations and spatial stability of criminal event data at the micro-spatial unit of analysis in Vancouver, British Columbia. Methods. Geo-referenced crime data, 2003 2013, representing four property crime types (commercial burglary, mischief, theft from vehicle, theft of vehicle) are analyzed considering crime concentrations at the street segment and street intersection level as well as through the use of a nonparametric spatial point pattern test that identifies the stability in spatial point patterns in pairwise and longitudinal contexts. Results. Property crime in Vancouver is highly concentrated in a small percentage of street segments and intersections, as few as 5 percent of street segments and intersections in 2013 depending on the crime type. The spatial point pattern test shows that spatial stability is almost always present when considering all street segments and intersections. However, when only considering the street segments and intersections that have crime, spatial stability is only present in recent years for pairwise comparisons and moderately stable in the longitudinal tests. Conclusions. Despite the crime drop that has occurred in Vancouver, there is still spatial stability present over time at levels suitable for theoretical development. However, caution must be taken when developing initiatives for situational crime prevention.

The primary objectives of this research are (1) to introduce summary measures of concentration that are relatively new to our field; (2) compare four concentration measures to determine whether there are reasons to use one in favor of the others; and (3) apply the measures to a real-case data to further understand the concentration phenomenon. Using the crime data of Cincinnati, we compare four commonly used social science measures of concentration: Gini, Simpson, Shannon, and Decile indices. For some purposes, the measures are interchangeable, while for other purposes the measures may suggest different interpretations for the same set of data. This paper is the first quantitative comparison of multiple measures of crime place concentration. We describe the benefits and limitations of each index and the circumstances for which each is most useful. We also answer the question: is crime within street segments spread along the segment or is it concentrated at a few addresses, as most place-based crime studies have overlooked the interior variability of crime on street segments.