Princeton and Palo Alto stand out in a graph of car-free households vs college degree holders in the US. (Click to expand.)

Where do graduates from top-ranking colleges go to work after they finish school? New York, Boston, Washington DC and San Francisco are popular destinations. In all these places, lots of people live without cars. Is that generally true of places where college graduates live? And where does Princeton fit in?A recent article, ‘Why Do The Smartest Cities Have The Smallest Share Of Cars?‘, which appeared in ‘The Atlantic’, analyzed data from the American Community Survey (ACS). The ACS regularly measures household size, number of children, family income, education, and- crucially- how many cars a household has. It is updated annually by the US Census Bureau. So, is there any link between the percentage of people in a city who have a college degree and the number of households that don’t have cars?

Based on an analysis of 20 large US cities, it turns out the answer is ‘yes’ (see chart above). Washington DC, Boston and San Francisco have lots of college graduates and high proportions of households without cars. El Paso, TX on the other hand, has relatively few college grads, and also has fewer households without cars. Lots of other cities are in the middle, but in general, the more college grads a city has, the more households live car-free. Thompson concluded as follows:

“I think what we’re looking at here is an underlying variable of city density. Highly productive cities that are magnets for talented (and rich) people tend to be crowded with twentysomethings trying to start their careers. Small crowded cities get clogged, and clogged cities require the kind of effective public transportation that makes cars an expensive nice-to-have rather than a have-to-have.”

Of course, the link could be explained by other factors, or could be entirely coincidental. This graph, showing an apparent link between organic food and autism has been going around the web recently, showing how statistics can be used to imply all kinds of tenuous theories. The other problem is that it’s easy to find some pretty huge outliers that don’t fit the pattern of “more college grads = more car-free households”…and one of those is Princeton.

We looked at two medium-sized towns- Princeton, NJ (obviously), and Palo Alto, CA- home of Stanford University, Hewlett-Packard and Tesla Motors. Both of these towns have stratospheric rates of bachelor’s degrees among their residents- over 75% in each case. But both towns have relatively few households without cars. 13% of households in Princeton lack cars- a figure that many people will find quite high. But it’s actually really low if you compare it to what is found in larger cities with high proportions of college grads. Both Princeton and Palo Alto lie well away from the other cities measured, and clearly do not fit the same rules.

What do you think? Why do cities with more college grads have higher percentages of car-free households? And why do Princeton and Palo Alto not fit the trend? Do you believe that today’s college graduates seek out places where they can live car-free? Have your say with the comments form below!