Fair enough, and thanks for links, but it sill looks like economy me picking to me, except for that second descending lick/run in the first video. And frankly he doesn't do many runs where economy or alternate picking matters. It's mostly arpeggio sweeping and single string stuff, at least in his instructional videos.
Instructional videos, yeah, the majority of his stuff he shows is either arpeggios or single string, But if you listen to any of his songs, there are so many runs that are more or less straight up or down the scale. A very concrete example would be Blitzkrieg, particularly the beginning. It's just A harmonic minor straight up and down. Songs such as black star or far beyond the sun (or practically every other instrumental of his) also have a lot of scale runs thrown in everywhere. So whether you alt pick or economy pick is about as important in an Yngwie song as a Paul Gilbert song, maybe more.
And of course, after spending disturbingly long time intently focusing on his right hand, it is starting to look more and more like economy.
The descriptive yet somewhat vague words usually associated with it (smooth, not as aggressive as alt, etc) also seems to match up with his sound. I guess he may very well pick like this.
And yes, an economy picker generally would care more about the number of notes he plays per string more, because it changes the way you pick. It still matters very much either way, as the only difference in techniques is whether to do 2 downstrokes in a row or skip over the string for an upstroke. I personally find the biggest problem with economy picking in 2 string runs on the high e and b strings. things like the famous paul gilbert example can be somewhat awkward (Especially with strings that have a higher tension, so not in Yngwie's case) as it quickly becomes nothing but inside picking.