For 10 points, name these economically entities used by governments to raise money.
The "Pigouvian" type of these things are used to correct negative externalities. Their rate is plotted on the x axis of the Laffer curve. The rate of progressive ones rise with increasing value of the target. Some politicians and economists propose reforming these in the U.S. by levying a flat one. The 16th amendment allows the federal government to impose an income one. For 10 points, name these economically entities used by governments to raise money.
The "Pigouvian" type of these things are used to correct negative externalities.
{taxes}