The Overoptimism of Research Assistants

How long will it take to fix the health exchange website? I have no idea. But thinking about this issue reminded me of a time when I was a grad student, and Larry Summers was an assistant professor. 

Larry told me that his research assistants always vastly underestimated how long any task would take. His rule of thumb: Double the estimate the RA gives, and then move to the next higher time unit.

So, if the RA says the task will take an hour, it will take two days.  If the RA says it will take two days, it will take four weeks.