Spain-STING — Banco de España's Real-Time Nowcasting Model for Spanish GDP Growth

Banco de España has operated the Spain-STING (Short-Term Indicator of Growth) nowcasting tool since the model family was introduced by economists Máximo Camacho and Gabriel Pérez-Quirós. It estimates a common latent factor from indicators available before official GDP data are released, giving policymakers a real-time read on the Spanish economy weeks ahead of Eurostat's confirmed figures.

The 2024 work aimed to fix a known weakness: the model's accuracy had degraded during the high-volatility pandemic period, so the authors sought to respecify it while preserving its established pre-pandemic performance.

In Occasional Paper 24/06 (published 4 March 2024, later in Revista Economía v.48), Banco de España economists Ana Gómez Loscos, Miguel Ángel González-Simón and Matías Pacce respecified the model with three changes: contemporaneous rather than purely leading indicator relationships, a stochastic (time-varying) process for the common component's volatility, and a revised, post-pandemic-relevant set of input indicators.

The paper reports a notable improvement in nowcasting performance during the high-volatility post-pandemic period while preserving the model's pre-pandemic accuracy, though it states this as a qualitative finding rather than a specific quantified error-reduction figure. The model sits within a wider, independently benchmarked family — Eurostat's 2025 statistical working paper on real-time GDP nowcasting for the euro area evaluates comparable tools across six member states including Spain, and sister models (Euro-STING, Ñ-STING) share the same architecture.

Spain-STING's forecasts and methodology are published routinely by the central bank rather than held as an internal black box, though it remains a statistical/dynamic-factor approach rather than a modern machine-learning system. Banco de España's own paper is candid that accuracy degraded during the pandemic before the 2024 fix, underscoring that even long-standing operational tools require periodic respecification.