By the mid-1930s, most economists had embraced what they considered the important contributions of the early Austrians. Fritz Machlup quoted Hayek's statement that "the greatest success of a school is that it stops existing because its fundamental teachings have become parts of the general body of commonly accepted thought". Sometime during the middle of the 20th century, Austrian economics became disregarded or derided by mainstream economists because it rejected model building and mathematical and statistical methods in the study of economics. Mises' student Israel Kirzner recalled that in 1954, when Kirzner was pursuing his PhD, there was no separate Austrian School as such. When Kirzner was deciding which graduate school to attend, Mises had advised him to accept an offer of admission at Johns Hopkins because it was a prestigious university and Fritz Machlup taught there.