The study applies spatial econometrics to the expenditures of the 262 municipalities of the Walloon Region (Belgium). It models the influence of expenditures from neighbouring municipalities on one given municipality. The independent variable coefficient is an indicator of a substitution-spillover effect when negative, and an indicator of a expenditure competition effect when positive. When we consider the municipalities of the Walloon Region, under our assumptions, the coefficient is significantly different from 0, and has for value + 0.81. The model does not confirm the existence a free rider / substitution / spillover effect but rather reveals significant expenditure competition effects. Each municipality apparently wants to provide a range of public local goods at least as wide as the neighbouring ones. Nevertheless the model is worth developing and some suggestions on how to do it are brought up in the final part. ; info:eu-repo/semantics/published