A question from Yahoo! Answers:
Why would economists consider a price ceiling on gasoline to be a really bad idea?
Because it doesn’t do anything to ensure availability. It doesn’t lower the cost of production or distribution, nor does it impact the reliability of supply. As a result, you can have gas stations that display low gas prices, but have no gas to sell.
In the Soviet Union, there were price ceilings on everything; as a result, the only thing they had in stores were price tags with affordable prices on them.
You may also think about it this way. High gasoline prices hurt most those who have the highest ratio of gasoline spending to disposable income. The pain, while real, is direct and focused. Gasoline price ceilings would hurt everyone, because people would waste enormous amounts of time in lines to gas stations (as they did during the last energy crisis). This pain would be no less real, but indirect and dispersed.