In the United States, you only pay certain taxes if you get a paycheck. These taxes are for Social Security and Medicare. Most importantly these taxes cap at around $60,000 per wage earner. The rationale is that these people are the ones most likely to use Social Security and Medicare, so they should pay for them. Of course, many people who get Social Security and Medicare never paid payroll taxes.

Payroll taxes are incredibly regressive and are hardly ever mentioned by people who support tax cuts. This is because cutting payroll taxes would only help people who make less than $60,000 a year (or $120,000 a year if you're married and you both work) and doesn't help the filthy rich who don't work for a living.

A large part of the marriage penalty is actually in payroll taxes since each wage earner pays them, and you can not file jointly for payroll taxes.

Raising payroll taxes is one of the tricks used to decrease the federal income tax rate without decreasing revenues. Since no one talks about them, you can stick it to the poor.

Ideally payroll taxes would be eliminated, and absorb into the federal income tax rates. Those rates could go up across the board by a few percent and likely pay for it, and give a bigger net tax cut to low-and-middle-class wage earners, with only a modest increase for the people who make large salaries.

Mind you, payroll taxes have nothing to do with the fact that wages have a top tax rate of around 36%, where capital gains are only taxed at 20%. This is why many executives are paid in stock options and not salary.