By the mid-1960s, both Marvel and DC were starting to reduce their page counts of story and art. Marvel pretty much settled on a standard page count of 20 starting around 1964 and stuck with that, while DC more commonly had 23-26 pages and gradually reduced that to a standard of about 23 pages by the end of the Silver Age.
But what about the number of words? Surely with all the anguished thinking going on in the minds of Marvel's tormented souls, Marvel comics had far more words per page than DC, thus making up for their lack of pages?
It's an interesting argument, and one I do not propose to settle with this post. But I thought I'd add a few data points to the debate, so I went back and picked (reasonably at random) Avengers #19 (August 1965) and counted the words on each page. Since the comparable DC comic is the Justice League of America, I picked JLA #37 (also August 1965) and performed the same task.
The results were somewhat surprising to me. The Justice League of America story had quite a bit more words than the Avengers tale, approximately 4,000 words compared to around 3,300, or about a 20% difference. The difference is largely caused by the additional pages in the JLA story; through page 20 (where the Avengers issue ended) the JLA story was only a little over 100 words longer, or about 3% more verbose.
Some other effects which are probably not surprising, but interesting nonetheless:
In both comics, the fewest words to appear on pages other than splashes or partial pages (the JLA story had three 2/3rd story and art pages with 1/3 page devoted to advertising) were the fighting sequences. In the JLA story, pages 12, 20 and 21 were the only pages aside from the splash not to have over 100 words, and those were the major combat pages. Who needs words when you've got one guy punching another? Ditto with the Avengers, where pages 4, 13, 16 and 17 featured characters more using their jaws to block fists rather than to talk.
I did not differentiate between dialogue and those scene-setting boxes at the top of panels, which was probably a mistake. Dialogue is always more interesting to the reader than exposition, and from a quick look it certainly appears that Marvel had more of the former and less of the latter than DC. Looking at the stories again quickly, the Avengers book had only 42 panels with scene notes, while the JLA story had 65.
Overall conclusions? There's not reall a significant difference between the number of words in Avengers #19 and JLA #37 beyond the obvious four additional pages of story and art. If I'd chosen two other issues I might have found something different.