shows that urban growth is also negatively correlated with confidence levels in the police and the judiciary. Others point out that rapid and poorly-managed urbanization can trigger a dynamic of mutual reinforcement between increasing crime rates and crumbling law enforcement institutions.<sup>81</sup> Fajnzylber et al. find a weaker correlation between urbanization and the homicide rate, but a more significant one with the robbery rate.<sup>82</sup> Thus robberies are likely related to population density and the social interactions that arise from it. A study on Colombian cities by Gaviria and Pages (1999) supports this conclusion, finding a strong correlation between crime and violence and a city’s growth rate.<sup>83</sup> Thus the authors suggest that a high incidence of crime and violence is to an important extent a reflection of many cities’ inability to keep up with an increasing demand for public safety brought by hasty and disorderly urbanization processes.

Drug production and drug possession are both significantly associated with higher crime rates. Fajnzylber et al. find that the incidence of intentional homicide is statistically larger in countries that produce drugs.<sup>84</sup> This goes with the popular view that violent crimes increase with drug trafficking and consumption. It remains to be studied, however, whether the incidence of homicides in drug producing and/or consuming countries is directly affected by drug-related activities or is the result of crime externalities of these activities. The drug possession crime rate is also positively associated with the robbery rate.<sup>85</sup> Econometric analysis has also shed some light on the phenomenon of criminal inertia, i.e. the persistence of crime over time. The regressions by Fajnzylber et al. reveal that crime and violence have an important inter-temporal dimension: current levels of violence influence future levels of violence. Current crime rates only respond to current policy variables with a significant lag.<sup>86</sup> The robbery rate also exhibits a significant degree of inertia, which is somewhat larger than that of the homicide rate. Sah (1991) points out that part of the problem may be that those living in areas with high crime participation rates can perceive a lower probability of apprehension than those living in areas with low crime participation rates, because the resources spent in apprehending each criminal tend to be low in high crime areas. Sah’s conclusion that past crime tends to breed future crime has important policy implications for violence prevention initiatives.<sup>87</sup> Among the structural factors which contribute to the legitimization of violence are a country’s level of impunity and corruption, racism, perceived lack of justice, and its links to social exclusion.<sup>88</sup> As mentioned in Section II, the high levels of mistrust of the police work to protect the criminals and explain the low levels of criminal reporting. The effectiveness of the police hinges on its relationship with the judiciary, i.e. on the effectiveness of criminal justice. Access to justice is especially problematic for the poor

> 81 Gaviria and Pages (1999). 82 Fajnzylber, Lederman, and Loayza (1998). 83 Gaviria and Pages (1999). 84

> Fajnzylber, Lederman, and Loayza (1998). 85 Ibid. 86 Ibid. 87 Sah (1991).

> 88 Moser and Van Bronkhorst (1999).

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