What explains the reduction of urban violence in Medellin, Colombia?

The world is currently undergoing the largest wave of urban growth in history. Most of this urban growth is occurring in the cities and slums of developing nations. While urban growth can bring many advantages, it can also bring new challenges in terms of conflict and violence or urban violence. High levels of violence and conflict are already being observed in Latin American urban environments. In 2015, 47 out of the 50 world's most dangerous cities were located in this region.Several theories have emerged since the early twentieth century to explain the emergence of violence in urban environments with the most widely cited coming from explanations of civil conflict, such as grievance perspective, greed hypothesis and structural violence. In reducing levels of urban violence and preventing future outbreaks, approaches developed in Western Europe and North America; social disorganisation, broken windows and social capital, are the most influential and have been subjected to considerable testing and analysis in upper-income urban environments. However, only in the last twenty years have researchers started to invest in better understanding what explains the emergence of the violence and the best approaches to reduce or prevent the violence in middle to low-income environments, such as Latin American ones. This thesis adds to the growing body of literature on the nuances of urban violence in middle to low-income environments by focusing on the case study of a Latin American city, Medellin, Colombia. This case study is a unique one for examining the emergence and reduction of violence in an urban environment for three reasons. First, no other city in the world has experienced such critical and high levels of violence. When Medellin was portrayed as the most dangerous city in the world with 381 homicides per 100,000 inhabitants, its homicide rate was almost 40 times higher than the United Nations definition of epidemic violence. Second, Medellin represents an extreme case of complex perpetrators of violence including drug cartels, gangs, youth assassins, urban guerrillas, community militia, paramilitaries and personnel. Lastly, no other city had experienced such a dramatic reduction in homicides in less than a generation. Medellin has experienced over a 90% reduction in homicides from 1991 to 2015.This thesis provides important lessons for urban violence prevention and reduction for policy makers in Latin America. By drawing from the conflict and development literature, this thesis uses a multifaceted approach to explain the emergence of violence in Medellin. The most influential urban violence policy approaches guide the discussion on the reduction of homicides in Medellin. From insights gained during the two periods of fieldwork in Medellin, this thesis employs concepts used in conflict and insurgency literature to analyse the different non-state armed groups in Medellin. These insights emphasise the need for policy makers in the region to take into account the processes of non-state armed group formation and maintenance in the reduction and prevention of urban violence