Speaking as an Economics major (which, by the way, is one of my biggest regrets in life, but I digress) I don't think micro-economics will help you one bit with what you want.
In that Joel says that a programmer who understands the fundamentals of business is going to be a more valuable programmer, to a business, than a programmer who doesn't. Many ideas do make sense in code, but not in business.
Then take business classes, not a social (pseudo) science class. Micro-economics won't tell you a thing about running a business, but it will help you identify market factors that can come into play that will affect your business, however, for the most part that is pretty obvious if you just sit and think about it for awhile.
That being said, there is a branch of economics that is possibly very beneficial to programmers and that is Behavioral Economics. Behavioral Economics mixes psychology with economics which can make for much better models (I know in school all our models were based on a rational human, which, as far as I can tell, doesn't exist). With behavioral economics, you could be a huge asset to a team by figuring out why people buy the way they do and then tailoring your product to that certain factor that causes people to buy. I'm sorry that I don't have any books for behavioral economics but there are some listed on the wikipedia.