This dissertation combines two empirical analyses related to the importance of security in Mexico. The first paper considers the impact of a major collapse in security by studying firms in large cities during outbreaks of violence. The second paper turns to rural areas and small-scale farmers, examining the effects of a land titling program that was designed to improve tenure security and increase agricultural productivity.Chapter 1 shows that indeed high levels of violent crime have substantial negative effects on firm outcomes. I study the economic consequences of recent high levels of violence associated with the Mexican drug war, relying on microdata from national business victimization surveys conducted in 2012 and 2014, and monthly pa...