What is nowcasting and why is it useful?
UNHCR publishes official statistics on forced displacement twice a year.
The statistics are published 4-6 months after the end of the reporting period due to the time needed for data collection, validation and verification.
For example, UNHCR's annual statistics are published in June and reflect the situation as of December in the previous year.
However, given the fast-changing nature of many of today's displacement situations, more timely statistics on forcibly displaced populations
are increasingly important.
Nowcasting - predicting the very recent past or the present - helps to estimate numbers in situations where statistics are not sufficiently timely.
In humanitarian and development situations, where collecting up-to-date statistics is challenging, nowcasting can be used to overcome reporting delays.
Examples of nowcasting initiatives within these sectors include the
WFP's HungerMap which monitors and estimates the current food security situation and
UNCTAD's interactive website displaying estimates of current GDP and trade indicators.
UNHCR has recently developed nowcasting of statistics on the refugee and asylum-seeker populations,
with estimates produced for the previous month on a rolling basis.
When new official statistics are released, the nowcasted estimates are realigned.
The estimates can therefore be best used to measure changes in the size of refugee and asylum-seeker populations
since the last published set of official statistics.
Figure 1 | Official and nowcasting statistics for refugees and asylum-seekers | -
How is UNHCR's nowcasting created and how accurate is it?
The nowcasting uses a mix of actual data and statistical models where actual data is not available.
These statistical models use historical information from various data sources to estimate the current refugee or asylum-seeker figures.
Updated on the 15th of each month, the nowcasted figures are estimates of the refugee and asylum-seeker populations at the end of the previous month.
Critically: nowcasted population figures are estimates and should not be considered as official statistics.
As with all empirical methods, the estimates have limitations. Overall, the global estimates of the total number of refugees and asylum-seekers has an accuracy of close to 99 per cent compared to UNHCR's official global forced displacement figures.
However, the accuracy for individual countries of asylum varies, given the reliance on different sources.
UNHCR continues to explore alternative methods and data sources seeking to further improve the accuracy of the nowcasting estimate.
What data sources and methodological approaches are used?
There are three key sources used to produce UNHCR's nowcasting data:
UNHCR's operational data
UNHCR's corporate case management system, ProGres, is used to register refugees and asylum-seekers in almost 130 countries.
About one-third of all refugees and asylum-seekers globally are registered in UNHCR's system.
The data is accurate, and it is maintained, validated and updated daily.
Government data
In asylum countries where refugees and asylum-seekers are registered by the host governments, publicly available data sources for asylum applications and decisions such as government websites or databases such as Eurostat are used.
The timeliness of this data varies. Where data is published with a delay, data gaps are filled by applying statistical modeling based on historical trends.
Predictive models
For countries without either UNHCR operational data or regularly published asylum data, the nowcasting model relies on estimates from a statistical model that predicts refugee flows between origin and asylum countries.
The model incorporates many factors that influence forced displacement flows between countries, such as the presence and intensity of conflicts and violent events, socio-economic variables, political, cultural and historical factors as well as geographic proximity.
How to use UNHCR's nowcasting data?
Explore the trends in figure 1 above and browse the
nowcasting data
in the Refugee Data Finder.
New data will be uploaded on the 15th of each month and relates to the population estimates on the last day of the previous month.
For each country, there can be up to two nowcasted datapoints published: for the latest month in the current year and the end of the previous year.
The source column in the data indicates how the nowcasted population estimate in each country of asylum was derived.
For some countries, nowcasted data is produced from more than one source.
Additionally UNHCR publishes the Nowcasting Brief, a short explainer document illustrating the more recent trends in the Nowcasting, as well providing updates on methodological changes.
The most recent Nowcasting Brief covers the period June 2023 to December 2023.
If you have any questions, feedback or suggestions for improving the nowcasting data (or the site more generally), please do
let us know using the feedback link at the bottom of the
home page. We will reply!
