The one thing I remember from tax class is the basic principle: Everything you earn is taxable, except <long list of exceptions>. Nothing is deductible, excep

The one thing I remember from tax class is the basic principle: Everything you earn is taxable, except <long list of exceptions>. Nothing is deductible, except <long list of exceptions>. When you add to either of those lists of exceptions, you're increasing the overall tax rate for people who can't take advantage of those exceptions.