However, given the sampling design, the survey is able to be used to identify how households were affected by the capture. First, the sampling design was such that respondents were randomized over space and time, and there should be no differences in the households surveyed in the months before and the months after the capture of the capital if the survey was conducted as planned (World Bank 2017).<sup>14</sup> Second, the survey is representative at the governorate/capital city level.

The 2014 HBS included a complete set of modules, including standard information on household consumption, employment, education, health, etc. that allow a thorough investigation of expenditure and household coping strategies. Appendix 1 presents summary statistics of expenditure and coping strategies, and demonstrate that households in Sana‘a were far better off than the rest of the country. Poverty in Sana’a was approximately one-quarter of the rate in the rest of the country, and all other measures were similarly better in the capital city. Additionally, women were significantly more empowered in the capital city than in the rest of the country, but subjective welfare was approximately equal across all regions of the country. However, it is important to place these characteristics in historical context- poverty has significantly increased in Yemen since 2005, in part driven by the political uncertainty of 2012 and also the sharp increase in food prices beginning in 2011 (e.g., WFP 2012; Dang and Ianchovichina 2016; World Bank 2017).

Another advantage of the 2014 HBS is that there was a nearly identical 2005 HBS that allow one to conduct additional robustness checks. One can investigate whether changes following the capture of Sana’a were potentially due to seasonal factors, or due to a country-wide shock as opposed to the capture of Sana‘a. In particular, the 2005 data allow an investigation of the difference-in-difference estimate of expenditure in Sana‘a following the capture of the city. Additionally, the data further allow us to investigate the triple difference as well, where the difference-in-difference estimate in the city of Sana‘a is compared to the difference-in-difference in the rest of the country. However, the women‘s decision-making module was not implemented in the 2005 survey, and specifications analyzing those measures can only analyze the difference in Sana‘a following the capture of the city in 2014, and compare that difference to the change in the rest of the country.

Although the household survey continued following the capture of the capital, the identification strategy requires the sampling of households to not significantly change following the capture. Importantly, given the lack of violence, the survey was reported to have been carried out as planned. All enumeration areas and initial households to interview were selected approximately a year before the city was captured, none of the enumeration areas were replaced, and there were no reports of difficulties in completing the survey in the final quarter.

Despite these reports of little trouble, it is always possible that enumerators consciously

> 14Roughly equal numbers of households were surveyed in each month, where 78 households were surveyed in October, 80 households were surveyed in November, and 77 households were surveyed in December. A total of 235 households were surveyed after the capture of Sana’a was complete and 269 households were surveyed in the 3 non-Ramadan months leading up to the capture. However, the responses to the women’s decisionmaking module were missing for one of the households in the pre-period, leaving one less observation in those specifications than the others. However, all results are robust to dropping that household from all specifications.

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