Who pays what in income taxes? With April 15 just around the corner, filers may be curious about where they fit into the system as a whole.

The individual income tax remains the most important levy in the U.S., providing nearly half of federal revenue. This is unusual: On average, developed nations get only one-third of their revenue from income taxes. Typically they also impose national consumption taxes, such as a value-added tax, that raise as much revenue as their income tax.

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