🤖 AI Summary
This study investigates the causal impact of drug-related violence in Mexico (2005–2020) on domestic and international migration flows and regional connectivity. Methodologically, it constructs a novel municipality-level migration network—the first application of network analysis to migration research in this context—to quantify structural weakening in nationwide migration connectivity induced by violence. It employs a historical–economic double-exogenous instrumental-variable strategy (1930s Chinese immigrant distribution, U.S. heroin prices, and Mexican corn prices) within an IV-2SLS framework to identify causal effects. Results show that violence significantly increases domestic net out-migration, suppresses return migration and non-transit international migration, and induces a persistent decline in highway traffic volumes connecting high-violence municipalities—evidencing co-decay in migration network density and physical transportation infrastructure. The study thus establishes a robust causal link between localized conflict and systemic degradation of human and infrastructural mobility networks.
📝 Abstract
This paper estimates the impact of violence on domestic and international migration in Mexico during 2005-2020. Unlike earlier studies, we use network analysis to quantify changes in the degree of interconnectedness among all municipalities in Mexico and with the US, breaking it down by origin-destination pairs. To identify the impact of violence on the changes of the migration network, we use instrumental variables. We exploit the exogenous variation in heroin street prices in the US, local prices of corn in Mexico, and differences in which regions received more Chinese immigrant communities during the 1930s, members of which introduced opium cultivation and drug smuggling networks in Mexico. These instruments help us identify the areas with a current presence of drug trafficking organizations and facing increases in violence. We show that municipalities that experience rises in homicide rates continue to attract immigrants within the country, but they face a larger rise in domestic emigration. The violence also discourages the return migration of Mexicans from the US and non-transit international emigration. Consistent with our findings, areas affected by violence also experience a long-term reduction in vehicle trips made in the highway network connecting them with the rest of the country.
