The age old question: Do dress codes at work make any difference on productivity or morale? It seems the scientific answer is that most studies show little to no effect in either direction. Here's a few blogs that get into this discussion in a little more detail: Productivity Blog, Culture in the Workplace, Andrew Jensen.
In the spirit of full disclosure, I will offer up that I am absolutely a jeans and t-shirt guy. So you can guess which side of the fence I fall on. Personally, I feel if I am comfortable, I am much more likely to be happy and productive. Business casual all the way for me! But, I absolutely think business professional attire is warranted at times. So basically, since company dress codes come down to company preference, here's the three basic questions to ask to determine which one makes the most sense.