The vast majority of the phone conversations I have with people are either on cell phones of via Skype. One of the consequences of this is the changing of the norms and expectations which accrued with telephone usage over the 20th century. For example, I don’t really know anyone’s number (does anyone know anyone’s “Skype number”?). Another dynamic I’ve noticed is the phenomenon of “sticky area codes.”
I’m going to be in Baltimore starting Wednesday and into Friday for ASHG. So I decided to email an old friend who I know from the Bay area, but who is actually a friend from my elementary school years back in the Northeast. When we both lived in the Bay we had atypical area codes. Mine was form the Northwest. His was from a New York City area code (where he went to medical school). It was absolutely no surprise to me that though he now lives in Baltimore he still has the same area code. I have other friends who have spent more than 10 years in the Bay area who retain their New York City area codes.
Here’s my hypothesis: the churn in area codes on cell phones over the past 15 years or so is basically modeled as neutral, with the exception of a few “prestige” area codes. As Dave Baltrus pointed out until recently area code portability wasn’t without friction. In particular you might have to get a new code (aligned with your residence) if you were switched carriers and such. But all that said, the prediction is rather straightforward, over time the proportion of prestige area codes should be increasing when you control for confounds. In regards to confounds, prestige area code residents were probably early adopters of cell phone technology. But now that the market has saturated and area code transition is relatively without friction my prediction is that there are is a notable bias in transitions away from non-prestige area codes, while prestige code holders are less likely to “mutate.”