In the absence of longitudinal panel datasets that follow migrants over time, the most suitable surveys are those especially designed to collect detailed retrospective information on workers’ migration and employment history. One early example is the survey of Turkish temporary migrants who went to Germany conducted by the German Institute for Employment Research (IAB) (Dustmann and Kirchkamp 2002). The IAB survey interviewed Turkish temporary migrants both at the end of their stay in Germany in 1984 when detailed retrospective questions were also asked about employment history in Germany, and after return to Turkey in both 1986 and 1988. However, the survey follows temporary migrants over only four years. In addition, the data were collected in the specific context of an assisted return program targeting Turkish migrants in Germany, and only samples return migrants that had applied to the program, which may affect the external validity of studies using this data.

Some dedicated migration surveys with detailed retrospective questions on past employment and migration overseas are cross-sectional. Among these relatively scarce surveys are the Mexican Migration Project (MMP)<sup>9</sup> and the Bangladesh Return Migrant Survey 2018/19 (BRMS)<sup>10</sup> carried out by the World Bank. The MMP is the most comprehensive survey to date to be implemented in an origin country. It captures both current and return migrants, along with the full employment history of all household members both in Mexico and abroad since the time they started working. It also records all trips overseas as well as internal migration episodes of all household members. In a very different context, the Bangladesh Return Migrant Survey collects the full employment and migration history of return migrants to Bangladesh who worked overseas under formal contractual temporary migration arrangements, primarily in the Gulf countries. The information captured includes detailed socio-economic and labor market outcomes before departure, during migration and after return, full migration history and a detailed breakdown of migration costs and sources of financing, along with savings and wage expectations prior to departure. Despite their comprehensiveness on migration and employment history, a potential drawback of these retrospective surveys is that they may suffer from imperfect recall by the respondents.

# **2.2.2 Data from destination countries**

The second category of surveys are implemented in destination countries. In these surveys, migrants are typically identified through a question on their country of birth. Identifying

> In contrast, surveys asking whether the member has ever lived abroad allow to capture a representative sample of the entire pool of returning temporary migrants.

> 9The Mexican Migration Project data set was used by Del ́echat (2001), Rendon and Cuecuecha (2010), Angelucci (2012), Reinhold and Thom (2013), Gorlach (2020), Massey, Durand, and Malone (2002) and Massey and Gentsch (2014), among others.

> 10For studies using the BRMS data set, see Ahmed and Bossavie (2022), Bossavie, Gorlach, Ozden, and Wang (2021), and Bossavie, Gorlach, Ozden, and Wang (2022).

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