Financial & Investment Dictionary: 

Marriage Penalty

Effect of a tax code that makes a married couple pay more than the same two people would pay if unmarried and filing singly. The Economic Growth and Tax Relief Reconciliation Act of 2001 gradually phased out the marriage penalty through 2009. This phaseout of the marriage penalty was accelerated in the Jobs and Growth Relief Reconciliation Act of 2003. This act increased the standard deduction for married joint filers to twice the standard deduction for single taxpayers and widened the size of the 15% tax bracket to double the size of the bracket for single taxpayers. ... 자료: http://www.answers.com/MARRIAGE%20PENALTY