The ICMS-Ecológico is a fiscal transfer mechanism from states to municipalities, implemented in the early 1990's in Brazil, to reward municipalities for the creation and management of protected areas. This paper investigates the efficiency of this mechanism by testing for the presence of interactions among Brazilian municipalities in their decision to create conservation units, in the state of Paraná, between 2000 and 2010. We estimate a Bayesian spatial Tobit model in order to analyze the behavior of municipalities. The empirical investigation reveals strategic substitutability in municipalities conservation decisions.
