The Fiscal Dividend Myth of an Income / GST Tax Switch

Reaping a windfall fiscal dividend from the taxation of the ‘underground’ economy's expenditures on ‘legitimate’ commodities is often seen as a significant advantage for a goods and services tax (GST) over an income tax. This claim ignores the changes in prices in the underground economy which would arise from the introduction of a GST. Employing a general equilibrium model which allows for tax evasion, we show that any ‘dividend’ arising from a change in the income tax/GST mix is equivalent to a rise in the income tax rate without a GST.