month, three months, and one year depending on the type of expense. Given the similarities between the change in food expenditure and the total household expenditure, it does not seem likely that the longer reference period of some consumption items is affecting the timing of the expenditure declines being uncovered in the baseline pattern.

Lastly, table 2 investigates potential heterogeneity in the drop in expenditure. Specifically, column (8) re-estimates the baseline specification, but restricts the sample to households where the head finished primary school; and column (9) re-estimates the baseline specification, but restricts the sample to households where the head did not finish primary school. The estimates in columns (8) and (9) demonstrate that the timing of expenditure drops varies between the two types of households. Less-educated households observe an immediate drop in expenditure in October, while one cannot reject the hypothesis at conventional significance levels that more educated households did not reduce their expenditure in October.<sup>22</sup> Thus, although there is an average drop in expenditure for all households by December, there is significant heterogeneity in when this decline in expenditure occurred. The results are consistent with better-off households being better able to cope with the occupation initially than less better-off households. Although the survey did not capture savings, one potential explanation for this pattern was that better-off households might have been able to rely more on savings than other households.

# **5b. Brief Discussion of Interpreting the Expenditure Changes**

The above expenditure patterns are consistent with the declines being caused by the capture of Sana’a. It is important to note that these results are robust to two important concerns. First, one might be worried about the possibility that the poor economic conditions might have led to the capture of the city by the rebels, and the above patterns are capturing this pre-existing trend (e.g., Miguel et al. 2004). However, the Houthi capture of Yemen‘s capital city is a setting in which this concern is minimized. First, expenditure was not trending in the months prior to the capture of Sana’a. Only after the capital was captured did expenditure begin to change. Additionally, the capture of the city appears to be more facilitated by powerful politicians rather than the will of either the rebels or the population in response to economic conditions. Although the Houthis took advantage of the anti-government protests in September<sup>23</sup> , their success seems more related to the fact that the majority of the army loyal to the former president did not resist the assault.<sup>24</sup> This is corroborated by the fact that the Houthis fought and lost numerous wars with the government over the prior decade, but only once the army did not resist their advances were they able to achieve more success.<sup>25</sup> Second, as is likely consistent with other conflict settings, the time immediately prior to

> 22See Appendix 6 for estimates of a specification that interacts the difference-in-difference coefficients with an indicator that the household did not finish primary school.

> 23See Al Jazeera (Accessed July 2017): http://america.aljazeera.com/articles/2014/9/25/houthi-yementakeover.html.

> 24See (accessed July 2017): http://www.reuters.com/article/us-yemen-security-salehidUSKBN0MM1MV20150326)

> 25See (accessed July 2017): http://www.aljazeera.com/news/middleeast/2014/08/yemen-houthis-hadiprotests-201482132719818986.html.

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