Abstract
The paper defines harmonic growth as a situation of diffuse well-being associated to an increase of GDP, and proposes a measures of time series similarity between GDP and each one from a set of social and economic indicators of development. Such indexes are then synthesized in order to provide the global degree of harmony in growth inside a country. A first Harmonic Growth Index is based on comparisons between couples of polynomials fitting the series. The second version of the index is obtained from cubic B-splines estimates. With an accurate selection of social indicators, both indexes can also be used to rank countries according to their level of development, offering effective complementary information to the Human Development Index.