Migration networks and risk diversification: How shocks in the US affect job search strategies in Mexico

过去五十年来，向发达国家的国际移徙人数大幅增加。这对目的地国和原籍国都产生了重大影响。人们普遍认为，移民促进了目的国生产率的提高。但是，尽管国际移民和汇款具有巨大的经济相关性，但我们对国际移民网络的发展影响仍然知之甚少。本项目调查国际移民对原籍国家庭决策的影响。虽然以前的文献主要关注汇款流入对收入的影响，但本项目试图确定，进入国际移民网络（我指的是移民与其留在家乡的家人和朋友之间的网络）是否会对原籍国家庭产生事前保险效应。有大量证据表明，不确定性影响风险厌恶家庭和个人的决策。如果移民网络服务于收入多样化目标，那么它们也应该影响对风险敏感的家庭决策。例如，如果厌恶风险的求职者更喜欢低回报、低风险的工作，而不是耗时、结果不确定但质量更好的求职活动，那么通过移民网络提供保险可以提高工作匹配的质量，除了汇款流入的直接好处之外，还可以提高原籍国的福利。由于移民决策的内生性，本项目探讨了墨西哥和美国之间的移民网络受到的冲击，这些冲击会影响移民网络的（可感知的）有效性——即在未来发生冲击的情况下获得收入支持的可能性。此类冲击的例子包括针对特定目的地的移民法变化、驱逐出境做法或经济衰退。在第一步，该项目将探索新的数据来源（如社交媒体数据），以确定美国和墨西哥之间在次国家层面的特定区域移民网络。通过高频劳动力调查，它将分析这些网络的冲击如何影响墨西哥家庭的求职策略、职业选择以及最终的工作质量。该估算策略结合了墨西哥移民在美国境内典型目的地的空间变化，以及这些移民目的地地区的时变冲击，采用差异中的差异方法。这个项目产生的结果旨在对目前关于国际移徙的成本和利益的国际辩论作出说明，并阐明移徙决定的决定因素。

International migration to developed countries has risen substantially over the last five decades. This has had strong implications for destination as well as origin countries. It is generally agreed that immigration triggered productivity gains in destination countries. But despite the huge economic relevance of international migration and remittances, we still know fairly little about the development effects of international migration networks.This project investigates the effects of international migration on household decision making in origin countries. While previous literature has largely focused on income effects of remittances inflows, this project seeks to establish if having access to international migration networks – whereby I mean networks between migrants and their family and friends left behind – has an ex-ante insurance effect on households in origin countries. There is substantial evidence that uncertainty affects decision making of risk-averse households and individuals. If migration networks serve an income diversification objective, then they should also affect household decisions that are sensitive to risk. If, for example, risk-averse job seekers prefer low-return low-risk jobs over time-consuming job search activities with uncertain – but better quality – outcomes, then providing insurance via migration networks can improve the quality of job matches, and be welfare enhancing in origin countries beyond the direct benefits of remittances inflows.Due to the endogeneity of migration decisions, this project explores shocks to migration networks between Mexico and the United States (US) that affect the (perceived) efficacy of migration networks – in terms of the probability of receiving income support in case of a shock in the future. Examples for such shocks are destination-specific changes in immigration laws, deportation practices or economic downturns. In a first step, this project will explore new data sources (i.e. social media data) to identify region-specific migration networks between the US and Mexico at the sub-national level. Using high-frequency labor force surveys, it will then analyze how shocks to these networks affect households’ job search strategies, their occupational choices and ultimately job quality in Mexico. The estimation strategy combines spatial variation in the typical destination of migrants from Mexico within the US, and time-variant shocks in the region of destination of these migrants, in a difference-in-differences approach.The results produced in this project aim to speak to the current international debate on the costs and benefits associated with international migration, as well as to shed light on the determinants of migratory decisions.