happening on the outer edges of the region, such as those in Algeria (expulsion of Al-Qaeda in the Islamic Maghreb) and the indirect consequences of the broader Arab Spring and its indirect impact on trafficking related dynamics (arms, drugs – especially since 2005, contraband, and migrants). Additional factors such as a high population growth rate have wielded an influence on other factors including a large youth bulge heightening poverty and low employment issues to which climate vulnerability and now the COVID-19 crisis further contributes to form a dangerous “fragility trap”.

It is not the purpose of this paper to review all these factors, and many other researchers have aptly done so before.<sup>3</sup> Rather, it draws the focus on the issue of water for three reasons. First, water has been overlooked as a separate factor. It tends to be lumped with other environmental factors as a resource, and with the issue of access to basic services when talking of water supply. Climate shocks are taken as a given vulnerability of the region and, except for the case of extreme weather shocks, given a coarse “background assumption status”. Figure 1 above characterizes the climate on the African continent using data from Willmott and Matsuura (2001).<sup>4</sup> Specifically, the top panel plots a map of the means of annual evaporation, temperature, and precipitation over the 1990 – 2017 period in each location, while the bottom panel shows the inter-annual variability of these climate variables within a given location over the same period. The sharp spatial gradient in climate variables experienced in the Sahel region stands out, indicative of the fundamental nature of agroclimatic conditions in characterizing the region.

Second, most of the research available on fragility in the Sahel has been qualitative. This reflects data challenges found in Sub-Saharan Africa in general (limited granularity in available variables, sample size and time coverage etc.), and others more specific to the region – including important variation in population densities. Water data itself has long been known to be imperfect and requires triangulation to overcome poor in-situ data. Nonetheless, the comparative advantage of an econometric approach to this analysis is its systematic and reproducible approach combined with a search for causal inference that can help disentangle concomitant factors and events.

Third, an unprecedented mobilization of financial resources has been directed towards the region in recent years, prompted in large part by the 2012-13 Malian political crisis and the resulting militant Islamist occupation of the country’s northern territory. This crisis has led regional and global leaders to coordinate against the spread of political instability in the region and beyond. Over the next three years, the World Bank alone plans to support G5 Sahel countries with funding totaling US$7 billion. A substantial part of those resources can be expected to either directly or indirectly involve water resources. The evidence presented in this paper seeks to inform these future engagements, as well as additional post-COVID-19 recovery efforts, to prevent lock-in effects and unanticipated spillovers, with lessons that may apply well beyond the region.

# 4. Data Sources

This section presents an overview of the various data sources utilized in the empirical approach presented in section 5. The first empirical approach, discussed in section 5.1, builds on data compiled by Harari and Ferrara (2018). HF utilizes gridded spatial data for the period 1997 to 2011 to present a plausibly causal effect of climate on conflict occurrence for the continent of Africa. Specifically, to measure the impacts of

> 3 See, for instance Eizenga (2019) and Guillaumont et al. (2016).

> 4 Inter-annual variability is measured by the coefficient of variation (= σ_i/μ_i , where is the grid-cell). ii

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