Sometime ago I remember reading a study that indicated the way that publications from Chicago trained economists clustered in the Journal of Political Economy and those from Harvard, in the Quarterly Journal of Economics. (Maybe someone recalls the reference.)
I recently came upon an article about the respective hiring patterns of departments of economics, comparative literature, of mathematics. A similar type of clustering occurs in economics, but far more modestly in mathematics, where presumably ideology would not play much of a role.
Economists commonly describe the ideological clustering is a division between freshwater and saltwater economists -- because the conservative departments tend to be in the interior and the more liberal along the East and West coasts.
The author does not attribute the clustering to ideological influences, but one might suspect a reluctance of Chicago to dilute its ideological purity with an excessive influx of people who do Harvard or MIT style economics. Admittedly, the difference between these schools is much more modest than it has been in the past.
If one can accept the possibility of mutual discrimination on account of relatively modest intellectual differences, might one be forgiven for suspecting the long-denied discrimination against radical economists?