Study Shows a Productivity Boost of Working From Home
I think it depends on what you want to optimize for.  If you want to optimize for individual productivity (and there are no trust issues) then sure, working from home is effective.However, you may decide that the individual productivity loss of having people work in an office is outweighed by the group productivity and morale gain from having people working together.  Here are some reasons from a holistic company perspective for requiring people to work out of the office:- To more effectively add to the culture of the company.- To take part in ad hoc training opportunities, either to teach someone who needs help, or to learn something from someone when an obstacle is encountered.- To be able to attend in-person meetings or stand-ups when urgent things come up - without the awkwardness and delays of conferencing in multiple people.- To provide mentorship to junior staff.- To collaborate more effectively.- To show clients/prospective clients, partners and recruits, a vibrant and energetic team and working environment that is worth investing in/joining.- To build morale and a sense of teamwork and camaraderie.At the same time, measures need to be taken in the office working environment to ensure that individuals can be productive, which means providing quiet working spaces, enforcing do-not-disturb rules, etc.Last point.  To anyone who is running a business where your employees can easily choose to work from home for any company in the world, such as software engineers: creating a vibrant company culture is one of the ways in which you can attract and retain team members.  Many people like being part of an in-person team and working with each other on a regular basis.  But if they're already working from home and rarely seeing their co-workers, what difference does it make if they choose to work for some startup out of SF?