Restroom Breaks

Recently, a Ford Motor company in Wayne, Michigan began monitoring employee's restroom break time, hoping that shorter breaks would cut company costs. The Chrysler Industry, on the other hand, sees the opposite side of this situation. They believe that by cutting an individual's breaktime, it may effect the way they work resulting in a change in productivity.
Do bathroom breaks really effect the way an individual performs on the job? How much of a change in costs should be expected if bathroom breaks are monitored, if any?