Decomposition of the h-index

I introduce a decomposition of the h-index, which is nowadays the leading criterion to assess the relevance of a scientist in his/her research field. According to the proposed decomposition, the h-index is the product of two indicators, the first of which measures the impact of the scientist on the research community and the second may be seen as a measure of concentration of the citations in correspondence of a reduced number of papers. The decomposition is illustrated by an application based on data concerning a group of top level economists.