Luigi Biggeri is Professor Emeritus of Economic Statistics at the University of Florence (Italy). He has been President of the Italian Statistical Society (SIS) and of the Italian National Statistical Institute (Istat). He did scientific works in all areas of economic statistic and, in particular, on the theory and practice of the Index Numbers, publishing more than 30 papers on this field. In the ‘80s, he published a paper on the accuracy and precision of the Consumer Price Indices (CPI) and during the same period proposed a general framework on the error evaluation of the estimates of National Accounts aggregates and of the industrial production indices. During the last two decades, He continuing works on index numbers and in particular on Sub-national Spatial Price indices.