This paper analyses the effects of the change in the US sales tax on economic activity and city size using a computable general equilibrium (CGE) model. Previous works have been designed to isolate the effects of a sales tax change on the particular parameters, such as city size, non-central retail activity and the value of housing. This research summarises the effects of a change in the sales tax rate on all the relevant variables in the context of one model. The underlined theoretical foundation is tested using data collected for the city of Fort Collins, a jurisdiction of approximately 100 000 people in northern Colorado, USA.