The department has published a number of studies in the past that showed that according to economic models, from an economic efficiency point of view, the consumption tax is the most efficient. With that being said, however, there are a number of factors entering into the decision as to whether or not to reduce a particular tax. There are, of course, other criteria such as administrative simplicity, fairness, and so on and so forth. But if we believe these models, the consumption tax is the most efficient tax.
On May 10th, 2006. See this statement in context.