Aaron, Henry J. and Harvey Galper, “Assessing Tax Reform,” The Brookings Institution, Washington, DC, 1985

“A national value-added tax would require a wholly new administrative apparatus for which neither the Internal Revenue Service nor any other federal agency now has the staff.  A new staff, estimated to number about 20,000, would have to be hired and trained.  Businesses would have to be educated about the new tax and would have to organize their accounts to comply with it.  Individuals would have to familiarize themselves with the tax as well and be prepared to accept the probabable increase in retail prices when the tax takes effect.
Experience from Europe suggests that a value-added tax could not be implemented in the United States in less than two or three years.  Most European countries had broad commodity taxes in place before they enacted the value-added tax, but they still took eighteen months to two years to implement it, p. 114