Matthew Turner and Diego Puga from the University of Toronto along with Henry Overman from the London School of economics and Marcy Burchfield are going to be publishing the results of their research next month . They have findings which do a good job of forcing a longer look at the nature and causes of urban sprawl by challenging existing thought on the subject. It turns out , amongst other things, that people are cheap and oblivious to the big picture. When they have to pay for infrastructure directly they opt to condense cities in order to reduce the amount of infrastructure required to support them. It is another case in which things reflecting their true lifecycle cost deter users from being wasteful. It may seem obvious but this is pretty important stuff.