Resumen
This paper presents empirical evidence on the relationship between public expenditure and economic growth, in Colombia for the period (1905- 2010) under the methodology know as times series, addressing two major approaches: endogeneity and exogeneity. The first states that spending is endogenous, procyclical, elastic against the product, while the second is considered exogenous and countercyclical. The first perspective is known in economic literature as Wagner´s Law, and the second follows a Keynesian behavior. However, it is important to note that under these two scenarios, it is possible to have a mixed approach, the characteristics of which are due to endogenous and countercyclical behavior of government spending to GDP. The results suggest that the series are not stationary, i.e. they are integrated of order one. For its part, the Johansen cointegration´s test indicates the existence of a long-term relationship between GDP and public expenditure. In addition, there is a strong support for the Wagner´s Law, because the direction of causality runs from GDP to public spending, and the elasticity coefficients are positive and significant.