Jerry Muller and Noah Smith ask the question. Muller writes,
Jews had a religious culture that promoted universal adult literacy – at least for men – and a culture that respected book learning. Those attitudes and dispositions were transferred from religious texts to secular forms of education. As a result, Jews were highly oriented toward education, and willing to defer current pleasures and income to obtain more of it.
Maristella Botticini and Zvi Eckstein in The Chosen Few say that the literacy requirement had huge selection impact. Jewish farmers were unable to comply with the requirement, and so they exited the religion. People who remained Jews tended to be more urban in their outlook and of course with greater aptitude for literacy.
Might matrilineal descent also have an impact? Jewish mothers are more educated, other things equal, and so children of Jewish mothers are (other things equal) more educated, and most important, learn the value of education and books.
I am not Jewish but my wife is, and she comes from a family of writers, professors, lawyers etc. The joke is, ”In this family if you have a Masters degree you are an underachiever.”
But wouldn’t your child be equally influenced by your paternal descent?
Look up what Greg Cochran and Henry Harpending have written about this.
Of course this varies greatly from country to country and century to century. But for a long time in Eastern Europe, Jews were excluded from farming (which was seen as the most profitable line of business) and were thus “relegated” to jobs that others saw as weird, like lawyering.
But if the question is asked now, in my experience it is almost always due to the questioner not knowing enough Jews. People know some Jewish bankers or TV show hosts, but they would never know if their bus driver or the nurse or the homeless guy in the park is Jewish.
To channel Edward Banfield, it may not be that Jews are “willing to defer current pleasures and income to obtain more of it [education]” but that they are more willing to defer current pleasures and income period.