ria, Somalia, South Sudan, and Yemen (e.g., UN 2017). The increased attention to the food emergencies in these countries, including Yemen, potentially increased the amount of assistance as well.<sup>6</sup> Another potential reason for why the 2017 IPC announcement had a larger impact than previous announcement was the turbulent time in Yemen’s conflict surrounding the announcement. There were many conflict-related shocks that had the potential to adversely impact food access during the same time period. Figure 1 presents a timeline of major events over the time period beginning in the second half of 2016.

First, the internationally recognized government began paying public sector salaries infrequently in the third quarter of 2016 (e.g., OCHA 2016), and this event has been widely cited as a primary driver of increased food insecurity in the country for the approximately 30 percent of the population that worked for the public sector (e.g., OCHA 2016, WFP 2016). Second, a cholera outbreak in Yemen began in October 2016, and re-emerged in spring of 2017 (e.g., OCHA 2017). The epidemic interacted with food security, where weakened immunity due to malnutrition made individuals more susceptible to the illness, and the illness further eroded the ability of households to earn a livelihood (e.g., OCHA 2017). Third, there was a significant escalation of violence during the latter half of 2017 that affected the port of Al Hudaydah, which limited the ability of the country to import necessary fuel, food, and medicine (e.g., OCHA 2017, Tandon and Vishwanath 2020, etc.). And lastly, there was a complete air and sea blockade of the country during November 2017 that had an adverse impact on food access and access to a number of basic services, most likely through a large increase in fuel prices (e.g., Tandon and Vishwanath 2020).

# **3. Data**

As discussed above, it is very difficult to collect data that can assess how food assistance responds to food emergencies given the difficult environments in which many of these events occur. This article utilizes the mobile Vulnerability and Assessment Mapping Survey (mVAM) conducted by the World Food Programme (WFP). The survey is the most geographically complete survey covering both the time before and the time after the 2017 IPC announcement. Furthermore, the survey is conducted every month, which further allows us to more completely analyze the persistence of changes in food assistance and food access.

Specifically, the monthly mVAM began in August 2015 and has been conducted in nearly every month since.<sup>7</sup> The 10-minute survey is conducted by mobile phone and reaches approximately 2400 households every month through random digit dialing. The survey is stratified by governorate, where potential respondents continue to be contacted until a sufficient number of 6One example is the Famine Action Mechanism announced by the World Bank immediately following the global reporting on food emergencies. The mechanism aimed to identify famines and food emergencies earlier and also automatically link funding to well-defined triggers. The countries cited in the development, and included in the piloting of the mechanism, were the four countries identified in the U.N. Security Council meeting and subsequent news reporting- Nigeria, Somalia, South Sudan, and Yemen (e.g., World Bank 2018b).

> 7In the 2016 IPC classification, the mVAM was actually the key component of determining food access across the country.

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