Academic books about entertainment often seem to miss nostalgia and zing, just as entertaining books about academics seem to pale without satire or criticism.

Ted Merwin’s “In Their Own Image: New York Jews in Jazz Age Popular Culture,’ might have been the exception given his educational background, fluency in the subject and tangible interest. But his book proves better in theory than in practice.

Happily, it does offer some new ideas about a familiar subject.

The first generation of immigrant talents and ingénues bid farewell to their weeping mothers in the shtetl and left for the rush of the New World. The second generation left them in boroughs for the rush of the Big City. Both experienced heartbreak when told they were too Jewish, or that they could play the Jew because they weren’t too Jewish. Or that, since they talked with their hands, they should play Italians, or since they could do Yiddish accents, they should try an Irish brogue.

What’s uncommon, Merwin writes, is that, rather than adopting new characteristics or a province of assimilation, Jewish entertainers used their own mannerisms, perspectives and humor, creating a place for themselves in pop culture and an image of identification for all American Jews, first or second generation.

Bravely picking at the scabs grown over painful stereotypes, Merwin examines the “if you’ve got it, flaunt it” school of Jewish entertainment.

The thesis of his segment on Jews in vaudeville builds on the idea that these Jews were really, really Jewish, even while playing WASP, Italian or Irish characters. His section on Broadway focuses on “Abie’s Irish Rose,” a play both wildly popular and wildly criticized during its run in the 1920s.

The final chapter, on silent movies, takes “The Jazz Singer” to task before breaking down themes of other films — some as universal as “rejecting the parents,” others as specific as “transcending the Lower East Side.”

Actor Harvey Fierstein’s voiceover for the 2005 documentary “From Shtetl to Swing” was so memorable, one might begin reading Merwin’s book and immediately hear Fierstein’s rocks-in-a-blender rasp in their head. Eventually, it may be only that imagined voice that holds one’s interest.

Though clear and articulate, Merwin’s writing can also be pedantic; the book evidently went through a lengthy metamorphosis — it was once an article, then a dissertation — and never really lost that donnish style. Just when you’re geared up for another yarn about Harry Jolson (Al’s brother) or Groucho Marx, Merwin’s sonorousness kicks in:

“As I will demonstrate, they seemed to be equally successful in performing openly Jewish material as they were when performing non-Jewish material. But I will argue that even their performances of non-Jewish material inescapably had a Jewish tam (Yiddish for ‘taste’ or ‘flavor’),” etc. These theses are inescapably over-explained and become tiring, but this might not entirely be the fault of the author who, perhaps tellingly, thanks his analyst before his editor in the acknowledgements.

Merwin, a professor of Judaic studies at Dickinson College, has missed a fine opportunity to discuss the development of Jewish identity and pop culture with charm and humor.

“In Their Own Image: New York Jews in Jazz Age Popular Culture” by Ted Merwin (215 pages, Rutgers University Press, $23.95).