More from the article...

... But it might just be critics saying that. That's according to a new study that discovered that the sophomore slump effect"where a band's second album is exceptionally bad compared to their first and third records"only crops up among professional critics, not fans.

"If every music critic has heard of a sophomore slump and everyone knows it happens, they might be convinced to over-apply it in their reviews," said Gregory Webster, Ph.D., the R. David Thomas Endowed Professor of Psychology at the University of Florida and co-author of the new study in the journal Psychology of Music. "We suspect it's a kind of social conformity, which we see in a lot of social groups." ...

imo, of course the second album will be judged at a lower level than the first.

Well, duh.

The first album represents going from zero to something.

That can be an infinite gain.

The second album goes from that "something" of the first album to some other "something."

That second gain will never be as large as the first because the first was based upon zero.