# **Attrition**

Following this protocol, the enumerators were able to conduct detailed follow-up survey with 2,799 initial respondents (or their family members) between March 26 and April 24, 2015.<sup>28</sup> This represents 84 percent of the overall sample, 85 percent of the inexperienced potential migrants, 86 percent of the experienced potential migrants, and only 78 percent for those who had an existing contract abroad and were back only on a leave. Since the main outcome of interest of the study is migration, attrition from the survey is also potentially an outcome to the extent that I am less likely to obtain information about a migrant.

I consider three separate measures of attrition. The first, Attrition-F, considers whether the full follow-up survey was conducted or not. The second, Attrition-M, considers whether it was possible to determine the migration status of the initial respondent. This measure differs from the first measure when enumerators were able to determine the migration status of the individuals but were not able to conduct the full follow-up interview. The attrition rate, according to this measure, is 13 percent for the overall sample, 12 percent each for the samples of inexperienced and experienced potential migrants. Among the 13 percent of the subjects with unknown migration status, it is possible to know about the attempted calls to the numbers provided by them. The phones of many in this group were switched off or not in operation, but for a few, the numbers provided were wrong (confirmed either by the telephone operator or by the person who answered the phone). In very few cases, the respondents refused to identify themselves or provide any information on the study subjects. Hence, my third measure of attrition (Attrition-W) indicates confirmed wrong numbers or refusal to interview. According to this measure, the attrition rate is about 3 percent in the overall sample as well as the subgroups.

The first measure of attrition, Attrition-F, is correlated with the information treatments. As the top panel of Table 4 shows, this measure of attrition is higher for death information treatments (marginally significant) and lower for wage information treatments (columns 1 and 2). For the inexperienced potential migrants, the ‘high’ wage information reduces this measure of attrition by 4 percentage points, significant at 10 percent level (columns 3 and 4). For the experienced potential migrants, the ‘low’ death information increases attrition by 6 percentage points (column 5).

The second measure of attrition, Attrition-M, is also correlated with information treatments. As the second panel of Table 4 shows, this measure of attrition matches the correlation pattern observed for Attrition-F. For the overall sample, death information treatments increase attrition whereas wage information treatment reduce it (columns 1 and 2). For the inexperienced potential migrants, in particular, the ‘high’ wage information treatment lowers this measure of attrition by 4 percentage points (columns 3 and 4). Whereas, for the experienced potential migrants, the ‘low’ death information treatment increases attrition by 6 percentage points (column 5).

The third measure of attrition, Attrition-W, is not correlated with any of the information treatments (bottom panel, Table 4). This measure of attrition is low and, more importantly, not correlated with the treatment status. Particularly for the inexperienced migrants, even the direction of the effects does not match the pattern observed for other measures of attrition.

Furthermore, attriters look broadly similar to non-attriters except for a few characteristics.<sup>29</sup> Attriters, by all three measures, have similar characteristics as non-attriters in except for completed years of schooling. For both the subgroups, I cannot reject the joint null that attriters and non-attriters have the same age, geography and locations. However, attriters have lower completed schooling by more than 1 year compared to non-attriters. This also makes some intuitive sense as those who have fewer years of schooling are likely to have fewer cellphones in the family or could be more likely to misreport phone numbers. However, as seen in Table 4, correlation patterns between treatments and attrition measures remain the same despite adding controls, including schooling.

More importantly, attriters, as classified by the first measures, Attrited-F and Attrited-M, had anticipated earlier migration even during the initial survey in January. In the initial survey, respondents were asked to assign 10 tokens to five bins representing their likely time of migration: 0-3 months, 4-6

> 28Follow-up surveys ended after a 7.8 magnitude earthquake struck Kathmandu on April 25, 2015, one day ahead of the planned end date. In the last working day (April 24), only 26 interviews (0.9 percent of total successful follow-up interviews) were conducted. When the follow-up interviews were in full swing, about 120 successful follow-up interviews were conducted in a day.

> 29Results not shown, but available on request.

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