I'm a liberal.
I can say this because I don't believe that our government should interfere with trade.
Since I have a dislike of Socialism in almost all of its forms, that makes me a liberal.
I'm a liberal because I'm against price supports, minimum wages, and most other government interference with market pricing.
Here's an interesting post on how the word "liberal" has gone even further from its original meaning. Here's a Samizdata post entitled "An American Liberal Becomes A Real One".
It's funny how the meaning of words can change.