I haven't heard of a more elegantly concise and apt way to describe the way liberals view economic interaction and free markets than the term 'sanguine'.
From wikipedia, sanguine from the four temperaments is described as:
A person who is sanguine is generally light-hearted, funloving, a people person, loves to entertain, spontaneous, has leader abilities, and is confident. However they can be arrogant, cocky, and indulgent. He/She can be day-dreamy and off-task to the point of not accomplishing anything and can be impulsive, possibly acting on whims in an unpredictable fashion.