The good folks at the CFAP have been heavily promoting some of the results of this model, that predict that Rhode Island will enjoy a tremendous economic boom if only we would eliminate our sales tax.
As I detailed in that article, the RI STAMP model is flawed not only by a host of questionable assumptions, but also the laughable attempt to obscure those assumptions under an absurdly over-complicated presentation of the relevant equations. Really, there is no reason to do what they do except as a conceptual bulwark against reporters who are easily cowed by that sort of thing.
Now comes the Institute for Taxation and Economic Policy (ITEP) to say the same thing as me. In an epic takedown (summary , report ), they cite STAMP’s many assumptions that either cannot be justified by the research literature or are completely contradicted by that literature or by experience.