A major strength of disaster inventories is their ability to record shocks at any time they occur so long as they get reported. Over the long run, this means that coverage of shocks improves as shock recording in underlying sources gets more exact and comprehensive.<sup>37</sup> In contrast, temporal coverage in microdata is intermittent: limited to the years in which the survey is implemented and the recall period of the survey.

# **Detail of available information**

The breadth of coverage in disaster inventories across time and space often comes at the cost of limited detail and missing information.<sup>30,37,48</sup> This particularly concerns the economic and welfare impact of shocks which are often difficult to quantify, especially so for uninsured damages.<sup>37,40</sup> Detail and completeness of the available information in disaster repositories is thus related to the size and salience of a shock. Further, the data provided in disaster inventories typically offers little opportunity for disaggregation, be it by affected population groups, geographies, or other key variables. As a consequence, disaster inventories often lack sufficient information to quantify disaster impacts on (asset) poor but highly vulnerable population groups.<sup>21</sup> As microdata sources elicit shock reports directly from those affected by them, they offer a high level of detail and completeness of information even for small or idiosyncratic events, for shocks that affect poor or marginalized population groups, and for their impact on uninsured damages and other, less salient domains of disaster impact. Depending on the design of the survey, shock and impact recording is often highly granular and allows for disaggregation and analysis along a broad range of ancillary information collected in the survey.

# **Accuracy of data**

Data recorded in disaster inventories typically relies on reports from one or few sources. Especially where events are small and therefore only reported in a single data source, this exposes disaster inventories to possible inaccuracies in the source from which information is drawn.<sup>37</sup> Even though reports of the number of people affected and the economic impact of any disaster are almost always estimates, disaster inventories rarely provide information that quantifies the uncertainty associated with any individual or collection of estimates.

Estimates from microdata, on the other hand, are based on a large number of data points collected from the population of interest. This also allows to explicitly quantify (part of) the uncertainty inherent in estimates of disaster impact. While the large samples underlying estimates from microdata attenuate the effect of inaccuracies in individual data points, microdata, as any data source, is still subject to possible systematic measurement error.

# **Comparability of source data**

Disaster inventories, and EM-DAT in particular, stand out for their broad coverage of events across geographies and time. To achieve this, disaster inventories need to rely on a wealth of different sources that vary according to their reliability, reporting standards, and definitions. Such idiosyncrasies are seldom 43