"Latvians (who also had higher literacy rates than the rest of the populace of the former Russian Empire), made it up to the very top of the communist elite. It was hardly surprising that, by the end of the 1920s, four out of eight of the top chiefs of the secret police (so-called collegium) came from the former Jewish Pale; this is explained by the high educational requirements for such positions."

http://www.history.ac.uk/reviews/review/1861