Impact of Governmental Actions on Sao Paulo city Collection

The aim of this paper is to present quantitative statistical methods for testing hypotheses regarding the impacts of governmental actions on the collection of taxes imposed by the main city; under Complementary Law 116/2003, which broadened the scope of services that could suffer impact from ISS to increase revenues without increasing tax rates. This study seeks to isolate government action effects from other factors' effects such as economic growth and inflation. Once isolated the effects of each specific action, a statistical model is created to compare the tax revenue evolution assessed on two occasions, before and after the action effective date. Statistical models for isolating econometric trends in time series through the use of multiple regression and variable "dummy" (qualitative) method are part of the tools used in the study. Validation of the effects was done by means of statistical significance tests. As a result, we conclude that there are significant effects of government action on the collection of taxes assessed.