He doesn't describe his methodology, but I can compare to my projections. The only difference in result is that I project a seat to VA instead of to OR. But he acknowledged that OR was #435 and VA was at #437 on his list. However, beyond #437 his bubble list is quite different than mine.
I used the July 2011 estimates and the April 2010 Census base to get an annual growth rate. This correctly accounts for the 15 month period between the Census and the estimate. I then applied the annual growth rate to the 2010 reapportionment population to get the 2020 projection. This accounts for the extra overseas population used in reapportionment but not for redistricting. Ten years is a long stretch for a simple model like this, but here are the projected changes.
CA +1
CO +1
FL +1
IL -1
MI -1
MN -1
NY -1
NC +1
OH -1
PA -1
RI -1
TX +3
VA +1
WV -1
The bubble seats in this projection are based on the last five awarded and the next five in line.
The last five awarded are CO-8, AL-7, VA-12, CA-54, and FL-28 (#435).
The next five in line are WV-3, OR-6, NY-27, AZ-10, LA-7.
