Public perceptions of tax fairness often have little to do with tax fairness as perceived by economists, says Steven Sheffrin, a professor of economics at UC Davis who recently published a paper on this issue. "There is a good deal of evidence in support of the proposition that the public is ill-informed about taxes, that taxpayers underestimate their tax rates, that they dislike taxes in proportion to their visibility -- like income property and gas taxes," says Sheffrin, director of the Center for State and Local Taxation. So how progressive should the tax system be? Sheffrin's research indicates that the public has a mild preference for some progressivity in the tax structure but that there is not an overwhelming demand for it. Sheffrin's findings also show that many people do not understand basic principles of taxation and how taxes affect the economy.