If you like, you can reference this PDF, which is one of the most recent studies on how using multiple monitors changes productivity. I’ll try to summarize the article and really hit on the main points, supplementing them with my own experience.
There are some basic numbers in the article that really stand out. In one test, going from a single monitor to a dual monitor cut the time it took to perform a task from 19 minutes to 16.5 minutes. This 2.5 minutes easily adds up over the course of a day. If a person averages 3 20 minute tasks per hour, and saves 2.5 minutes per task, they will save 60 minutes over the course of the day. If you stretch this out over the course of a year, you go from roughly 260 days of work to 292. A second monitor is a small investment for an extra 32 days of productivity over the year. While these numbers are of course the ideal scenario, they were experienced in the study. Even if they were cut in half, we’re still looking at a really good increase.
Other than the raw performance increase in productivity, dual monitors are also just easier to work with. Speaking from experience, they help to cut down on feeling rushed or stressed, and make it easier to focus on the task at hand. An employee will spend less time trying to find what s/he was trying to do, and more time doing it. Personally, nothing is more frustrating to me than switching out of a window to find information I needed, only to be interrupted. With dual monitors, this isn’t a big problem, as chances are your previous task is still right there, but if you only have one screen you may find your primary task buried under a bunch of to-dos and that can make it difficult, frustrating, and stressful to try to get your work done. As business owners, you know that once employees become visibly frustrated with the tools they have to work with, it becomes much harder to get them to work productively.
This is a short post today, but there is so little ammunition to fire against the dual-monitor argument. I can’t think of anyone whose productivity would not increase by doubling their available work space. I suppose I should note that I use 3 monitors myself. I wouldn’t have it any other way.