Are those even his titles? Authors generally don't make up the title themselves. Sometimes they can help pick one from a list created by a title editor.
In the fiction publishing world, authors generally do make up their own titles. The editors at the publishing house might exercise veto power and/or make their own suggestions, but I don't think I've ever heard of novelists and short story authors not being allowed to title their own work, with the exception of work-for-hire jobs, e.g., writing a book in a series whose "author" is actually a pseudonym or writing for a book packager.
Most of the above are his titles. Some which were published in serialized form before being published in a single volume (Martian Time-Slip and We Can Build You) had different titles. Letters, manuscripts, and publication notes are helpful to shed some light on this matter; e.g. The Transmigration of Timothy Archer was regularly referred to as the "Archer novel" or "Bishop Timothy Archer".
I think my definition of "most" (11 of 14) and your definition of "most" (4 of 14) differs here...which is fine. We live in the "days of Perky Pat" anyway.
In total, I count 14 books with titles chosen by the publisher/editor:
Do Androids Dream of Electric Sheep?
Dr. Bloodmoney
The Simulacrum
Ubik
We Can Build You
Martian Time-Slip
The Transmigration of Timothy Archer
The Divine Invasion
A Maze of Death
Counterclock World
Radio Free Albemuth
Solar Lottery
The Zap Gun [1]
The World Jones Made
Among his notable works, the only titles PKD came up with were The Man in the High Castle, VALIS, Flow My Tears, Palmer Eldritch, and A Scanner Darkly.
So. Yes, most.
Editors changed his shorts, too. I love the title "I Hope I Shall Arrive Soon", but PKD wanted to call it "Frozen Journey".
[1] This one was unusual in that the editor gave PKD the title and asked him to write a plot around it.
I'm just pointing out that my comment was about the list provided by the commenter above and "most" was about that list rather than all of PKD's work. What you refer to as "pedantic", I consider precision and talking about what's being discussed; someone asks "are these his titles", the answer was "yes. most of these are". Nothing more, nothing less.
