Quantil, Bogotá, Colombia.
Facultad de Economia, Universidad de los Andes, Bogotá, Colombia.
PLoS One. 2024 Mar 12;19(3):e0294020. doi: 10.1371/journal.pone.0294020. eCollection 2024.
Despite the common belief that police presence reduces crime, there is mixed evidence of such causal effects in major Latin America cities. In this work we identify the casual relationship between police presence and criminal events by using a large dataset of a randomized controlled police intervention in Bogotá D.C., Colombia. We use an Instrumental Variables approach to identify the causal effect of interest. Then we consistently estimate a Conditional Logit discrete choice model with aggregate data that allow us to identify agents' utilities for crime location using Two Stage Least Squares. The estimated parameters allow us to compute the police own and cross-elasticities of crime for each of the spatial locations and to evaluate different police patrolling strategies. The elasticity of crime to police presence is, on average across spatial locations, -0.26 for violent crime, -0.38 for property crime and -0.38 for total crime, all statistically significant. Estimates of cross-elasticities are close to zero; however, spillover effects are non-negligible. Counterfactual analysis of different police deployment strategies show, for an optimal allocating algorithm, an average reduction in violent crime of 7.09%, a reduction in property crimes of 8.48% and a reduction in total crimes of 5.15% at no additional cost. These results show the potential efficiency gains of using the model to deploy police resources in the city without increasing the total police time required.
尽管普遍认为警察的存在可以减少犯罪，但在拉丁美洲主要城市，这种因果关系的证据存在差异。在这项工作中，我们通过使用哥伦比亚波哥大特区一项随机控制警察干预的大型数据集，确定了警察存在与犯罪事件之间的因果关系。我们使用工具变量方法来确定感兴趣的因果效应。然后，我们使用汇总数据一致地估计条件 Logit 离散选择模型，这使我们能够使用两阶段最小二乘法为犯罪地点确定代理人的效用。估计的参数允许我们计算每个空间位置的犯罪对警察存在的自有和交叉弹性，并评估不同的警察巡逻策略。平均而言，暴力犯罪的犯罪对警察存在的弹性为-0.26，财产犯罪为-0.38，总犯罪为-0.38，所有这些都是统计学上显著的。交叉弹性的估计值接近零；然而，溢出效应不可忽视。不同警察部署策略的反事实分析表明，对于最优分配算法，暴力犯罪平均减少 7.09%，财产犯罪减少 8.48%，总犯罪减少 5.15%，而无需增加总警察时间。这些结果表明，在不增加所需总警察时间的情况下，使用该模型在城市中部署警察资源具有潜在的效率收益。
