The 631,306 Alaskans that received a PFD in 2014 incudes children, students studying out of state, and military personnel claiming Alaska residency, but the 361,130 IRS taxpayers are only heads of households and adult filers living in state.  To compare accurately, you should reduce your 631,306 number by at least the 209,290 dependents listed in the IRS data (line 15 in the IRS data).  The result, 422,016, means that about 57% of adult Alaskans had income more than $25,000.