When I asked my management for dual monitors for our development team, I was promptly asked to provide justification for the request. I hope the research I used for to support my case is helpful to others who may find themselves in the same boat.
Numerous studies have proven that providing staff with a multiple monitor setup is a cheap means of increasing productivity. The results of the studies vary in the specific numbers, but overall, teams can expect anywhere from a 10 - 50% increase in an individual's productivity, which results in a simple return on investment. It is estimated that the cost of the hardware necessary to setup dual monitors for an individual would pay for itself in a matter of weeks.
One study conducted by the NEC, ATI and the University of Utah showed that individuals were "10 percent more productive", "increased their errorless production by 18 percent" and were "29 percent more effective for tasks, 24 percent more comfortable to use in tasks and found it 39 percent easier to move around sources of information".
The use of multiple monitors as a cheap way of increasing productivity has been written about in publications ranging from the NY Times to ComputerWorld. Multiple monitors allow a developer to multi-task easily, which I have found invaluable. For example, I can work on a piece of code while monitoring a log output of a batch job running on test server all at the same time.
Even Bill Gates has weighed in on the topic on a few occasions, and details the importance of dual monitor screens in his own office setup:
"If you look at this office, there isn't much paper in it. On my desk I have three screens, synchronized to form a single desktop. I can drag items from one screen to the next. Once you have that large display area, you'll never go back, because it has a direct impact on productivity."
My favorite article on this topic so far has been Jeff Atwood's Programmer's Bill of Rights, which list a number of rights that every programmer should be entitled to, first on that list being:
"Number 1: Every programmer shall have two monitors
With the crashing prices of LCDs and the ubiquity of dual-output video cards, you'd be crazy to limit your developers to a single screen. The productivity benefits of doubling your desktop are well documented by now. If you want to maximize developer productivity, make sure each developer has two monitors."
As a programmer, if you have not already transitioned to a multi-monitor setup, I highly recommend it, even if you add a monitor to your laptop setup. Just send your boss this blog post.