There are so many trends that effect why men and women work in the occupations that they do. During the late 1920s, more men returned to teaching. And after World War II, because of the GI Bill we saw more men going into education than ever before in history.
We now have two things going on that may be a "perfect storm" of having more men go into education.
1) More men are losing than jobs than women. According to a New York Times article last year:
