Relevance of an accuracy control module - implementation into an economic modelling software

Economic modelers or econometricians know that they have to control the accuracy of the computations, to get their results safe. Unfortunately, even if a few softwares allow to control it (especially in using an interval arithmetic), most of them are presented like black boxes, from an arithmetical point of view. We have tried, in this paper, to provide the point of view of a macroeconomic modelling software’s builder. After having recalled the accuracy problem and its solutions (algebraic and arithmetical), we'll present the GNOMBR software we have developed, based on multiple precision arithmetic methods. Then we'll present an application to an input-output model. Then we'll give elements to conclude to the relevance of this technique.