This paper applies a Machine Learning approach with the aim of providing a single aggregated prediction from a set of individual predictions. Departing from the well-known maximum-entropy inference methodology, a new factor capturing the distance between the true and the estimated aggregated predictions presents a new problem. Algorithms such as ridge, lasso or elastic net help in finding a new methodology to tackle this issue. We carry out a simulation study to evaluate the performance of such a procedure and apply it in order to forecast and measure predictive ability using a dataset of predictions on Spanish gross domestic product.

Subnational jurisdictions, compared to the apparatuses of countries and large institutions, have less resources and human capital available to carry out an updated conjunctural follow-up of the economy (nowcasting) and for generating economic predictions (forecasting). This paper presents the results of our research aimed at facilitating the economic decision making of regional public agents. On the one hand, we present an interactive app that, based on dynamic factor analysis, simplifies and automates the construction of economic synthetic indicators and, on the other hand, we evaluate how to measure the uncertainty associated with the synthetic indicator. Theoretical and empirical developments show the suitability of the methodology and the approach for measuring and predicting the underlying aggregate evolution of the economy and, given the complexity associated with the dynamic factor analysis methodology, for using bootstrap techniques to measure the error. We also show that, when we combine different economic series by dynamic factor analysis, approximately 1000 resamples is sufficient to properly calculate the confidence intervals of the synthetic index in the different time instants.