This dissertation explores how individuals understand and evaluate risks when making migration decisions. Migration entails serious financial risks, including upfront payments to labour brokers or human smugglers whose promises of abundant job opportunities, decent wages and safe working conditions may not materialize. In order to understand why some individuals decide that these risks are worth taking, I examine how migrants evaluate these risks when making their decisions. I draw upon multiple empirical strategies including (1) original ethnographic fieldwork amongst Thai migrants in Los Angeles, USA, (2) a survey and a lab-in-the-field experiment with prospective migrants in northern Thailand, and (3) a natural experiment leveraging individual-level census records documenting migration experiences within Vietnam. Most scholarship on the micro-level determinants of migration choices sets out from a standard expected-utility model according to which migrants assess the potential benefits against the costs of migration, weighted by the probability that such outcomes will occur. While this basic economic model of migration decision-making has helped to shed light on some migration patterns, I propose to extend the model by incorporating sociological insights in order to gain a better understanding on an old puzzle, namely why some people move while others decide to stay given that they face the same socio-economic conditions. In particular, this dissertation is composed of five stand-alone, but related empirical chapters, in which I examine the role of social preferences, biased beliefs and superstition in migration decisionmaking. My findings show how relative deprivation (i.e. the perception of being economically left behind) and beliefs about luck aect evaluations of risk, and consequently, migration decisions. Overall, my results assert that there are many yet under-explored but important factors influencing how individuals assess risks during the migration decision-making process.