The value-added tax, first proposed in 1918 by a German industrial executive, was discussed sporadically for more then three decades before it was actually implemented. A modified version was adopted in 1953 by the state of Michigan and repealed in 1967; in 1954 the central government of France imposed such a tax, and most European and many other countries have since followed suit. Some people have advocated the inclusion of a value-added tax in the US federal tax system to provide a revenue source to supplement the income tax or substitute for part of it.