L’Indicateur Synthétique Mensuel d’Activité (ISMA) : une révision

This paper proposes new bridge equations for the Monthly Index of Business Activity (MIBA) published by the Banque de France. The MIBA is a forecasting tool for the quarterly GDP growth in France both for the current quarter and the next quarter, originally based on the surveys in the industrial sector published in the Monthly Business Survey (MBS) conducted by the Banque de France. Two improvements are suggested: first, from a technical viewpoint, we use an automatic model selection procedure which brings a robust, clear and systematic framework for selecting variables; second, from a modelling viewpoint, we take into account the business surveys in the services sector published by the Banque de France. The forecasting performance of the different models is evaluated.