The summary statistics reveal several important basic insights. Population-weighted average IPC ratings across districts generally are lower than simple averages, indicating that food insecurity is more common in sparsely-populated districts. The minima and maxima highlight that most countries have at some point experienced crisis or worse, but famine declarations (IPC rating of 5) are extremely rare occurrences. Zambia is the only country in our sample that has not experienced food crisis in this period. The number of observations available in each country is listed, with “Crisis+” denoting the number of food crisis observations. “Outbreaks” correspond to the subset of food crisis observations that were preceded by a phase 1 or phase 2 observation. Predicting these transitions into food crisis is the primary goal of this paper. While approximately 16% of observations correspond to food crises, only a small share of these classify as transitions into new outbreaks of food crisis (1,723/6,143 _∼_ 28%). This highlights why the issuance of timely warnings is important: over two-third of classified transitions into crisis are followed by extended periods of crisis, at which point it is too late for prevention.

Table 1: Descriptives of FEWS NET ratings aggregated to admin2, netted of humanitarian assistance effects, used for estimation and cross-validation.

|||**IPC Rati**<br>|**ng**<br>||**Crisis **<br>|**Indicator**<br>||**Observat**<br>|**ions**<br>|**Co**<br>|**verage**<br>|
|---|---|---|---|---|---|---|---|---|---|---|---|
|**Country**|Mean|Pop. Mean|Min|Max|Mean|Pop. Mean|Total|Crisis+|Outbreaks|Districts|Time Periods|
|**Afghanistan**|1.41|1.40|1|4|0.08|0.07|1,224|94|59|34|36|
|**Burkina Faso**|1.08|1.08|1|3|0.00|0.00|1,440|5|5|45|32<sup>_c_</sup>|
|**Chad**|1.45|1.41|1|4|0.10|0.09|2,448|251|129|68|36<br>|
|**Congo, Dem. Rep.**|1.91|2.00|1|4|0.21|0.26|218|46|11|50<sup>_a_</sup>|8<sup>_d_</sup>|
|**Ethiopia**|1.83|1.74|1|4|0.26|0.22|2,664|681|174|74|36|
|**Guatemala**|1.43|1.30|1|3|0.08|0.05|792|62|28|22|36|
|**Haiti**|1.51|1.38|1|3|0.07|0.04|1,512|103|64|42|36|
|**Kenya**|1.46|1.42|1|4|0.08|0.08|2,556|213|60|71|36|
|**Malawi**|1.48|1.48|1|4|0.16|0.16|972|152|87|27|36|
|**Mali**|1.19|1.10|1|4|0.04|0.01|1,800|68|48|50|36|
|**Mauritania**|1.43|1.44|1|4|0.07|0.09|442|32|16|13|34<sup>_c_</sup>|
|**Mozambique**|1.18|1.13|1|3|0.05|0.04|396|21|7|11|36|
|**Niger**|1.36|1.27|1|4|0.07|0.05|2,412|173|94|67|36|
|**Nigeria**|1.78|1.20|1|4|0.20|0.02|3,564|710|231|99|36<br>|
|**Somalia**|2.48|2.44|1|5|0.40|0.37|2,590|1,040|188|74|35<sup>_d_</sup>|
|**South Sudan**|2.13|2.16|1|5|0.33|0.35|2,808|937|232|78|36<br>|
|**Sudan**|1.41|1.34|1|4|0.10|0.07|2,640|265|107|80|33<sup>_d_</sup>|
|**Uganda**|1.10|1.06|1|3|0.02|0.01|2,016|33|12|56<br>|36<br>|
|**Yemen, Rep.**|3.42|3.26|2|4|0.93|0.89|960|892|35|69<sup>_b_</sup>|14<sup>_b,d_</sup>|
|**Zambia**|1.02|1.01|1|2|0.00|0.00|2,304|0|0|72|32<sup>_c_</sup>|
|**Zimbabwe**|1.54|1.44|1|4|0.17|0.13|2,160|365|136|60|36|
|**Total**|1.60|1.41|1|5|0.16|0.10|37,918|6,143|1,723|1,162|116 **months**<sup>_e_</sup>|

The descriptive statistics are calculated using FEWS NET ratings, netted of humanitarian assistance effects, taking admin2 districts as the level of observation. “IPC Rating” refers to the netted data on the original 1-5 scale, while “Crisis Indicator” refers to the binary indicators of phases (3) and above. The data dimensions under “Coverage” refer to the number of admin2 districts in the country, disregard of whether all of these districts cover livelihood zones that receive ratings from FEWS NET, and the number of assessment periods from the first assessment to the last (February 2019). The June/October 2019 and February 2020 assessments are used only for validation and not included in this table. Further guidance on data coverage is as follows: _a_ partially covered, _b_ missing at random, _c_ latest assessment periods missing, _d_ earliest assessment periods missing,<sup>_e_</sup> from first to last assessment: July 2009 - February 2019.

# **2.2 Covariates of food crisis events**

We forecast transitions into food crisis using only readily-observable covariates, available monthly at the admin2 district level prior to outcomes. We deliberately do not use lagged 5