A deep dive into missing data and the limitations of disaster databases.
If we want to reduce the risks of disasters, we need to track where they’re happening; what types of events they are; their human and economic impacts; and how these trends change over time.High-quality data helps us see patterns in the data on factors such as increased resilience, climate change, and humanitarian response.There are now several dedicated research groups that publish in-depth databases of disaster records.One of the most widely cited is the International Disaster Database (EM-DAT) of the Centre for Research on the Epidemiology of Disasters (CRED). It is open-access and free and lets anyone dig into the specific details of each recorded disaster. At Our World in Data, we rely on EM-DAT as our main data source for disasters. It’s also used by organizations such as the United Nations, World Meteorological Organization, UNFCCC, and many academic researchers.But no disaster database is perfect. Data is incomplete. Its quality varies over time. And some events are either unreported or hard to quantify.That’s why it’s important to understand the biases and limitations of data sources so that they can be interpreted usefully.Many of them are explained by EM-DAT itself in its documentation.In this article, we explore several of these biases, which can lead to incorrect conclusions when analyzing historical trends.The increase in the number of disasters is partly a result of reporting bias
Many smaller events in the past aren’t captured
We should be cautious about reporting increases in the number of disasters using EM-DAT There are large gaps in disaster statistics, especially for economic damages Heat deaths are poorly captured Failure to capture the indirect impacts of disasters