Oil prices have come down from their highs, but if you're still unhappy with the price that you're paying for gasoline, blame government.

Here's one way way that bad policy artificially increases the price of gasoline: minimum markup laws in 18 states prohibit retailers from selling gas below cost. Offering loss-leaders on some products for some amount of time is a standard technique on everything from a gallon of milk to electronics.

But it's an illegal practice in Wisconsin, which requires that gas retailers mark up their costs by at least 9.8%. The Wisconsin Policy Research Institute explains how this law harms consumers.