El Salvador homicide rates with geographic-shx.

Most violence in El Salvador has been attributed to gangs. After being one of the most violent societies worldwide, in 2023, the country’s homicide rate reached a low 2.4 per 100,000 population. The decline is the outcome of a security plan by government that has attacked gangs directly under a state of exception. Nearly 80,000 gang members have been incarcerated. For the past 30 years or so, Salvadoran authorities and politicians alike, have participated in negotiations with gangs to reduce violence and gain electoral support in exchange for benefits for their members. This research studies violence as the outcome from the activities by gangs, politicians and governments, their interactions, and communities intervening in the realization of these interactions. As most data required for explaining these processes is either inexistent or difficult to access, a hierarchical Bayesian model was implemented for the spatio-temporal evolution of homicide with random effects that account for omitted variables at the level of local areas and time periods. The results support the view that unobserved covariates related to the district patterns of homicide have evolved over time. Two cycles appear in the evolution of homicide over the period under study, one from 2003 through to 2012, and another starting in 2013 and still going on at the time of writing. This finding reinforces the view that timing of government-gang negotiations drove the behavior of homicide rates in El Salvador during 2002–2021 together with the growth and expansion of gangs as seen from clustering of high-risk districts over time. The incarceration of scores of members and collaborators has both incapacitated gangs as key producers of violence, and deterred other forms of crimes. As a next step, the government should build collective efficacy, in particular among disadvantaged communities, to restrain the formation of gang-like groups in the time to come.

萨尔瓦多的绝大多数暴力事件均与黑帮团伙相关。该国曾跻身全球暴力程度最高的社会之列，2023年其凶杀率降至每10万人口2.4的低位。这一下降得益于该国政府在例外状态（state of exception）下推出的直接打击黑帮的安全计划，目前已有近8万名黑帮成员被监禁。近30年来，萨尔瓦多的官方机构与政客均曾通过与黑帮进行谈判以降低暴力犯罪，并以向帮派成员提供优待为交换，换取其选举支持。本研究将暴力视为黑帮、政客与政府的活动及其互动，以及社区介入此类互动实施过程的产物。由于解释上述过程所需的多数数据要么缺失，要么难以获取，本研究采用分层贝叶斯模型（hierarchical Bayesian model）对凶杀率的时空演变进行建模，引入随机效应以考量地方区域与时间维度上的遗漏变量。研究结果证实，与各辖区凶杀模式相关的未观测协变量随时间发生了演变。在所研究的时段内，凶杀率的演变呈现两个周期：其一为2003年至2012年，其二始于2013年，截至本文撰写时仍在持续。该发现进一步佐证了以下观点：2002至2021年间，政府与黑帮谈判的时机，加上黑帮的发展与扩张（表现为高风险辖区随时间呈现集群特征），共同影响了萨尔瓦多的凶杀率走势。对大量黑帮成员及同伙的监禁，既削弱了黑帮作为暴力主要制造者的能力，也遏制了其他形式的犯罪活动。下一步，政府应着力构建集体效能（collective efficacy），尤其是在弱势社区当中，以在未来遏制类似黑帮团伙的形成。