Statistically, increasing the number of people in an area will increase the amount of crime, the same way increasing the number of people will increase the traf

Statistically, increasing the number of people in an area will increase the amount of crime, the same way increasing the number of people will increase the traffic or the water usage or the electricity usage. Most people also overestimate the costs of crime by a factor of about 15; see http://press.princeton.edu/titles/9018.html http://press.princeton.edu/titles/9018.html for more information. It's too simplistic to just consider that. It may be a valid concern but it's also valid to consider the rights of the person or entity that owns the land to build what they want on it, and the consequence of underbuilding and the subsequent effect on real wages. If you want to do it properly you'd want to consider the increase in crime from a marginal resident added to area X, vs. the increase in crime from wherever they would live if you didn't build more housing in area X. Not to mention the effect on crime from perpetual underbuilding and the subsequent decline in most folks' real wages...