Resumen de Conservation laws and symmetry in economic growth models: a geometrical approach

David Martín de Diego , Manuel de León

• The aim of the present paper is twofold. On one hand, we present a classification of infinitesimal symmetries for Lagrangian systems, and the corresponding Noether theorems. The derivation of the result is made by using the symplectic techniques. Some of the results were previously obtained by other authors (see Prince (1985) for instance), and an exhaustive presentation can be found in de León and Martín de Diego (1995, 1996). Let us note that these results are true even if the Lagrangian function is singular, which is usually the case in economic models. On the other hand, we apply our methods to derive some well-known conservation laws, in particular the income-wealth conservation law obtained by Weitzman (1976) and the Samuelson's first law (see Samuelson (1970)).