The objective of this paper is to explain the growth of public spending by the approach of the demand for public goods in Morocco from 1970 to 2010, to test the veracity of Wagner's law for the Moroccan economy by an approach demand, to verify the positive effed between the share of public expenditure to GDP ratio and the following variables: the per capita income, population, urbanization,
... [Show full abstract] degree of economic openness, the effed of Baumol and macroeconomic stability. We concluded from our study that Wagner's law holds for the Moroccan economy. Our model confirms the positive effed between the share of public expenditure to GDP ratio and the following explanatory variables: per capita income, the degree of economic openness, the effed of macroeconomic stability and the effed of Baumol. We also concluded from our study that there is a feedback relationship between public spending and per capita income using the Granger causality test.