Without getting actual location data from telephone companies or sampling cellphones nationwide, pollsters are forced to ignore people who move into a given state with an out-of-state cell number. Consider the manifestly unrepresentative sample that resides in my cellphone. Of the roughly 100 cellphone numbers I have saved, 49% are owned by people living (and presumably voting) in states that do not match their cellphone’s area code.
Because area codes didn’t cross state baoundaries, back in the old days of reliable landline polling, that made predicting state races relatively simple. But when it came to predicting House races, the patchwork of area codes made for complications that could skew a poll’s result.
We may have a similar phenomenon at the state level today. The above quotation comes from Dan Hopkins when he wondered a couple weeks ago about the geographic reliability of cell phone numbers since area codes effectively no longer stop at state lines. Undoubtedly this situation exists. However, it only effects polling if the population of out of state cell phone households users is politically different from the population of geographically consistent cell phone households. Not knowing who they are or how to contact them, we simply don’t know.
Ten years ago, even a luddite like me had a Tennessee area code but lived in Virginia. As more households go wireless and as labor portability continues to spread, this polling problem is likely to increase from year to year.
I wonder if some day, in order to get a representative sample, we’ll go back to actual in-person polling? Or perhaps we’ll go the full Rasmussen and use only internet polls?