Sin tax is a euphemism for a tax specifically levied on certain generally socially-proscribed goods - usually alcohol and tobacco. Sin taxes are often enacted for special projects - American cities and counties have used them to pay for stadiums - when increasing income or property taxes would be politically inviable. The proper name for such taxes is sumptuary tax.

Some jurisdictions have also levied taxes on illegal drugs such as cocaine and marijuana. Whether this actually qualifies as a sin tax is rather questionable, since such taxes are generally intended to create an additional punishment for trading, possession or consumption of illegal drugs rather than to raise revenue.

Such taxes have historically triggered rampant smuggling and flourishing black markets, especially if they create large differences in the price of popular products in neighboring jurisdictions. Critics of sin taxes argue they are regressive in nature and discriminate against the lower classes, since in many jurisdictions they are more likely to be consumers of alcohol and tobacco and more likely to consume a greater quantity of it. Furthermore, sin taxes not normally value added in nature meaning that expensive, high-quality product more likely to be purchased by the wealthy will have the tax comprise a much smaller proportion of its final purchase price, thus ensuring that the lower classes pay a much greater proportion of their lower income in tax. Critics also argue that the behavior affected by sin taxes are strictly personal and of no social consequence, and therefore should not be moderated by government.

See also

• Green tax shift
• Pigovian tax