Some will, some won't—it shouldn't change how cities adjust their transportation policies.
The ongoing discussion about Millennial car interest has been treated, rather strangely, as a zero sum game—as if anyone either always drives or never drives, with no behavior in between. So we get a somewhat unnecessary mea culpa from The Atlantic's Derek Thompson, whose fine past reporting has revealed key shifts in how young people feel about driving, upon discovering that some of them are actually buying cars. Citing data from J.D. Power, Thompson shows us that vehicle sales among Gen Y (here, meaning Millennials) have eclipsed those of Gen X:
The appropriate rebuttal from Joe Cortright at City Observatory is that of course Millennials buy a lot of cars—there's a lot of Millennials. Using Census data and previous J.D. Power measures, Cortright determines that once you account for generation size, Millennials "are buying new cars at a rate far lower than older generations." By his math, Gen Y buys 47.5 cars per 1,000 people, whereas Gen X buys 73.7 per 1,000, and Boomers buy 63.5 per 1,000.
An aside for the record: with the Census data Cortright appears to use, we get the same total number of Millennials (roughly 78 million) but more Gen X (roughly 49 million) and fewer Boomers (about 76 million). So the Gen Y rate of 47.5 per 1,000 remains the same, but Gen X slides to 67 per 1,000 and Boomers hop to 67.2 per 1,000.
Cortright doesn't give Thompson quite enough credit for nuance, but he's right to question the poorly defined J.D. Power figures. Their chosen birth-range of Millennials, from 1977 to 1994, is a clear red flag. Anyone who knows two people near either edge of that range—which includes both 38-year-olds and 21-year-olds—also knows that often the only label they share is "earthling." Any unifying behavioral conclusions drawn from such a diverse group should be taken with extreme caution.
Cortright is also sharp to point out that a better comparison would weigh the car-buying behavior of young people today with that of Gen Xers or Boomers when they were the same age:
Because automobile purchasing patterns vary over a person’s life cycle, you can’t accurately gauge the generational change in buying habits by comparing the current year buying habits of Millennials (average age, late 20s) with GenX (average age early 40s). The more interesting question to answer would be whether the average 25-year-old Millennial today is more or less likely to purchase a vehicle today than someone who was 25 in 2005, or in 1995 or in 1985.
That's data we'd love to see, too. Fortunately we have a decent proxy for it in the form of a recent Census tool that reveals car commute shares by young people in 1980, 1990, 2000, and 2010. But no single or simple conclusion about Millennial driving behavior emerges from this data, either. In some big transit-rich cities (such as New York and Portland, Oregon), young adults are driving to work less today than they did three decades ago. In more car-reliant or transit-deprived places (such as St. Louis or San Diego), the opposite is true.
So just as it's a little foolish to lump everyone born from 1977 to 1994 into the same category, it's equally unwise to think young people in vastly different environments will approach their daily travels the same way. There is a broad (if obvious) conclusion to reach here: people in dense cities with balanced mobility networks are all less apt to drive. As Emily Badger points out at Wonkblog, perhaps "Millennial" has just become a synonym for "city dweller" in the popular consciousness, even though the trend toward dense city living among young adults appears to be mainly among those with college degrees.
There is one other clear theme in American driving that cuts across all ages, which both Thompson and Cortright do note: per-capita vehicle mileage is down just about everywhere. By one recent analysis, not a single age group drove more in 2009 than it had in 2001. That broad trend away from previous driving habits, rather than the behavior of any ill-defined group, should serve as a loud enough alarm for cities to reconsider their car-first transportation practices.
Because the real question isn't whether or not Millennials will drive—answer: most will, some more than others depending on the place—it's how cities that endure the enormous social costs of driving can help everyone rely less on cars than they did in the past, old and young alike.