What is in a number? Some reflections on disaster displacement modelling

The rise in global displacement has inspired a wave of quantitative comparative research in recent years. While deeper systematic knowledge on contextual determinants of disaster-related mobility and associated risks is in high demand, quantitative modelling of human displacement should be exercised with care. This commentary reflects on three central challenges related to the quality of available displacement statistics. Future scientific progress in this field would benefit tremendously from harmonization and validation of displacement data that separate between distinct mobility responses.

The challenges discussed also offer insights of immediate relevance to stakeholders across the science-policy divide:

1. Be careful when conducting, interpreting and communicating statistical analyses of aggregate displacement data.
2. Avoid framing the number of displacements as an indicator of disaster severity.
3. Do not forget the invisible disaster victims.