RDP 2026-05: Real GDP Forecasts by International Organisations 3. Data

We examine annual real GDP growth forecasts at horizons of up to two years ahead. To this end, we assemble a large dataset incorporating the forecasts of prominent international organisations and the average of private-sector forecasters.

A strength of our dataset is that it covers as many economies as possible, and contains forecast vintages as recently as December 2025. The large set of economies allows us to draw conclusions about international organisations' forecasts in general, rather than worrying that our conclusions only apply to forecasts for a specific unusual group of economies, such as G7 economies. The inclusion of recent forecast vintages that were unavailable to previous researchers increases our sample sizes, which increases the relevance of our results to current practice at international organisations, and increases the power of our tests.

We use short-term forecasts for annual real GDP growth from four international organisations:

• The IMF publishes forecasts in the World Economic Outlook (WEO). A full WEO is released in each April and each October, which we call the ‘Spring’ and ‘Fall’ editions respectively, and provides forecasts for almost all economies. A WEO update is published in each January and July, which provides forecasts for selected economies and groups of economies.
• The World Bank publishes forecasts in the Global Economic Prospects (GEP) publication each January and June. The GEP provides forecasts for emerging and developing economies, and for selected advanced economies.
• The EC publishes forecasts for European Union member states and for selected other economies each Spring and Autumn, and sometimes at other times as well.
• The OECD publishes forecasts for OECD members and major non-members in the Economic Outlook (EO) publication each December and June, and occasionally at other times.

We also use the average of the forecasts made by respondents to the Consensus survey. The respondents are a mix of global institutions (e.g. global banks) and economy-specific institutions (e.g. local banks or think tanks). Around 20–30 forecasters are surveyed for each economy.

Table 1 summarises the forecasts available. This rich variety of data ensures a well-rounded view on the forecast performance of all major institutional and private economic actors, allowing us to draw general conclusions about the economic forecasting profession in the last 30 years. Both WEO and Consensus increased the number of economies for which forecasts are available over time, which means our evaluation is able to study more economies than similar evaluations conducted earlier. The GEP and EC produced forecasts for a mostly constant set of economies over time.

To assess forecast performance we must compute forecast errors at different horizons. We define the forecast horizon as the length of time from the publication date of a forecast to the end date of the target year (see Appendix A.1). We compute forecast errors as the latest vintage of the actual outcome minus the forecast (see Appendix A.2), except for some rationality tests, as discussed in Section 5.2.1.