vulnerability to climate shocks. We propose that indicators should be selected to capture two aspects of vulnerability: (i) a person’s physical propensity to experience severe income, asset or health loss, (ii) the ability of a person to cope with and recover from asset or income loss. In this paper we select indicators to cover both aspects using data that was readily available for multiple countries:

- For physical vulnerability we consider access to improved water and electricity. This is a very small set of infrastructure measures, driven in part by evidence in the literature, but also by what measures were readily available at the subnational level on a global scale. Other measures that could be considered are access to sanitation or irrigation, mobility and access to markets or services, investments in water drainage infrastructure, improved household dwelling structures, resilient farming practices, and access to early warning systems.

- For ability to cope and recover, we consider not having sufficient income to manage the impact of a shock; not having education to switch livelihoods or access information and resources to reduce income losses; not having access to public support; and not having access to financial services.

The selection of these variables is motivated further in a subsequent section, along with a description of the data used to measure them.

Transparency and coverage are important characteristics of a global measure. Transparency may require a certain simplicity, because a measure that becomes too complicated can be hard to interpret, and the drivers of change can be opaque. Coverage requires data being available for as many countries as possible and updated frequently over time. Although adding more dimensions of vulnerability is attractive given the multidimensional nature of vulnerability, this can often run counter to achieving simplicity and coverage. Survey data is the source of the indicators of vulnerability used here and survey data is unavailable for some countries on each indicator. Coverage sometimes declines when an additional indicator is added (World Bank 2018). It is thus important to ascertain that adding a new indicator adds value in that it allows a good number of people to be identified as vulnerable that would not have been identified without its inclusion. In other words, an indicator adds value when its correlation with other indicators is low.

In the absence of a model, an aggregation of indicators into a single index requires deciding how the different indicators are to be weighted<sup>4</sup> , whether to take into account the depth of deprivation on a given indicator, and on how many indicators a household has to be deprived to be considered vulnerable (see World Bank 2018 for a full discussion of considerations). We follow the approach of the World Bank’s multidimensional poverty measure (World Bank 2018) and present the number of people vulnerable according to each separate indicator and counting the number of indicators that individuals are deprived on. As with the World Bank’s multidimensional measure of poverty, the index is thus a simple expression of an approach whereby the number of deprivations for one person are counted (Atkinson 2003).

People at risk are people that are exposed and vulnerable. Figure 3 summarizes the measure, highlighting that someone is at risk if they are exposed, and vulnerable. While we propose this core structure of the measure of at risk, this still leaves much to be decided such as the selection of events, probabilities, indicators and number of events and indicators on which someone is exposed or vulnerable. We propose that someone is exposed if they are exposed to any one natural hazard and vulnerable if they are

> 4 Applying no weights is also a choice on weighting as it assumes all dimensions are equally important.

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